I always play c5 Sicilian, there are loads of variations on this opening, I would recommend some serious study time on it
A black defence to play against all E4 openings

if u want to play a system whatever opponents does, not a good idea (or maybe i misunderstood what u mean by all e4 openings).
Sorry but chess doesnt work like this.
Maybe u should try another game if u are disturbed by the complexity of the game?
If I remember correctly Seirawan suggested the Pirc in the last chapter of his 1999 book, Winning Chess Openings.
https://web.archive.org/web/20140627132508/http://www.chesscafe.com/text/hansen173.pdf
Haven't seen much of others agreeing with that suggestion. Other possibilities are discussed earlier in the book.

Dont worry about openings, your blitz rating is under 900, so that means that you are probably a begginer, your main problem is hanging pieces, thats what all beginners do, we all did that, so try to avoid doing that, dont study chess opening theory, just try to play logical moves, for examlpe, if your opponent plays 1.e5, puts a pawn on a central square, you go e5, he plays 2. Nf3, you play Nc6 and defend you pawn, that way of thinking is in my opinion the best way to learn chess, no need to study openings at that level, play some longer games, dont play to much fast games (3 or 5 mins), play 10 min games for example..

Xx
I use the Caro-Kann against 1 e4 and it's cousin the Slav against 1 d4 or 1 c4. Both openings have a goal of getting your Queen's Bishop off of c8 and into action on f5 or g4 and, depending on White's choice of a closed or open game - it's usually a problem getting that QB into the game in the French or Q's Gambit Declined. You can launch a Q-side attack, often beginning with c5 or pick away at his center pawn chain with f6 or c5, both of which are supported by posting you Queen's Knight at d7, which also takes away White N-Outposts at e5 and c5.
Note how all those ideas behind the similar openings mean you are guided if White leaves the book - you know what you want to accomplish in development and attack and the game often develops in ways for you to do it: though you have to be ready for a wide-open game if White chooses exchange variations and for a lot of maneuvering and seeking a one pawn advantage in closed ones.
Andy Soltis' book, A Black Defensive System for the Rest of Your Chess Career, c. 1997, is based on those two defenses. It gives very good general guidance, explaining the pawn structures you want to try to reach, etc.
Personally, I had been playing the Slav after 1 d4 d5 2 c4 c6 after getting stuck with an underused B at c8 when I played the QGD, ...2 e6 which - like the French - blocked in that Bishop. That led me to discover the Caro-Kann which is now my favorite: when White plays 1 d4 I usually play 1...c6 hoping for 2 e4 where 2...d5 transposes into the Caro-Kann. That led me to Soltis' book which provides a good knowledge of the ideas behind the openings.

Hi. Is there a decent defence I can learn play against all E4 white openings?? I've been trying the French but quite tired of it now. Many thanks in advance !
Xx

The Scandanavian defence (1.....d5) is a good one for less-experienced players, because there are not many variations. The Wikipedia page for it is very good.

Xx
I use the Caro-Kann against 1 e4 and it's cousin the Slav against 1 d4 or 1 c4. Both openings have a goal of getting your Queen's Bishop off of c8 and into action on f5 or g4 and, depending on White's choice of a closed or open game - it's usually a problem getting that QB into the game in the French or Q's Gambit Declined. You can launch a Q-side attack, often beginning with c5 or pick away at his center pawn chain with f6 or c5, both of which are supported by posting you Queen's Knight at d7, which also takes away White N-Outposts at e5 and c5.
Note how all those ideas behind the similar openings mean you are guided if White leaves the book - you know what you want to accomplish in development and attack and the game often develops in ways for you to do it: though you have to be ready for a wide-open game if White chooses exchange variations and for a lot of maneuvering and seeking a one pawn advantage in closed ones.
Andy Soltis' book, A Black Defensive System for the Rest of Your Chess Career, c. 1997, is based on those two defenses. It gives very good general guidance, explaining the pawn structures you want to try to reach, etc.
Personally, I had been playing the Slav after 1 d4 d5 2 c4 c6 after getting stuck with an underused B at c8 when I played the QGD, ...2 e6 which - like the French - blocked in that Bishop. That led me to discover the Caro-Kann which is now my favorite: when White plays 1 d4 I usually play 1...c6 hoping for 2 e4 where 2...d5 transposes into the Caro-Kann. That led me to Soltis' book which provides a good knowledge of the ideas behind the openings.
What you say makes a lot of sense. Makes me wonder why French and QGD is so popular.
Lakdawala has a book about c6. I haven't read it, but it looks like you might like it.
"come on... [Black Defensive System for the Rest of your Chess Career] is old and the coverage of the slav is nowhere near good enough. He tried to cover the whole Slav in about 20 pages!?!?! You will have to do much better than that if you want to play the Slav and Caro-Kan at a reasonable level." - CM Peppinu (~18 months age in a thread about the Soltis book)
"... For inexperienced players, I think the model that bases opening discussions on more or less complete games that are fully annotated, though with a main focus on the opening and early middlegame, is the ideal. ..." - FM Carsten Hansen (2010)
"... For beginning players, [Discovering Chess Openings by GM John Emms] will offer an opportunity to start out on the right foot and really get a feel for what is happening on the board. ..." - FM Carsten Hansen (2006)
https://web.archive.org/web/20140627114655/http://www.chesscafe.com/text/hansen91.pdf
One might also consider Openings for Amateurs by Pete Tamburro (2014)
http://kenilworthian.blogspot.com/2014/05/review-of-pete-tamburros-openings-for.html
https://chessbookreviews.wordpress.com/tag/openings-for-amateurs/
https://www.mongoosepress.com/excerpts/OpeningsForAmateurs%20sample.pdf

There are lots of good and fun options. Try an opening for a while to see if you like it. There are no openings that make chess easy or guarantee wins, and any opening you gain a lot of experience with can be a good weapon.

The modern/pirc is the universal solution to all openings
And since white can do literally anything, you have to be prepared for literally anything. There are no easy solutions.

Okay, I'll add my tiny knowledge:
When white plays 1.e4, one has to keep in mind one thing at all times until it becomes irrelevant: if black succeeds into playing d5 without facing too much negative consequences, they equalized.
That being said, you can divide, for the next black choice, and outside "specials" such as the Scandinavian Defense, what will follow into two clearly separate groups: white plays d4 soon, or keep the d pawn on d3, or even on d2 for a while. As soon white played d4, you'll enter the mainlines of any previous back choice for defense. And you'll need to know your set ups and move orders if you don't want to get "miniaturized" (beaten in less than 20 moves). As for the lines where white avoids playing d4 alltogether, black is free to build any sort of defense without dreading a blitz attack for not knowing their "religion".
So, all that having been said, do there is any "Universal" system that can ensure black to survive the dangerous e4/d4 white set up without learning too much theory? Well, the correct answer is: "yes and no". How handy...
Still, I can propose a set up for black, avoiding the well known lines of the Pirc and Modern Defense, that can delay the direct confrontation with the dangerous looking Bonnie & Clyde e4/d4. And funny thing, some specialist even named that set up "Universal Defense", when other prefeered to name it "Czech variation of the Pirc Defense", which doesn't make so much sense to me, when black will often, ultimately, and in a delayed fashion opt for a Philidor-like central pawns set up, Hannam style.
It starts anyway so: 1.e4-d6 2.d4-c6 (d6 and c6 can be, of course, interverted). The big thing of this system, is the opening of the d8/a5 diagonal for the Queen, which will provide the tactical and strange ressources, that makes it hard to refute.
Since, then, I think that set up changed name a dozen of times, but I can tell, I played it a lot in the late 90's, and scored both cool wins and dreadfull defeats. Cos guys, it's razor sharp and double edged, for both sides (unless you are an IM who will, caveman loke, go "Huhuhu! But I'll crushhh you easily with that, one!" which is only true cos your only a regular club player.
You'll find videos about it on Youtube, and can google "1.e4-d6 2.d4-c6 chess " and see what you find.
In case you feel like a bloodthirsty pirate, loving death and danger on the board like I do when I sit at the table. Well, more when I was younger, but it's a matter of temper.
Good luck.
P.S. you might have to insert Nf6 before playing c6, I don't remember for sure. You'll have to do the check on that one job...
The Scandi basically guarantees the game will steer into a direction you're more familiar with than your opponent, everything else gives white plenty of options. Although you shouldn't fear theory, if you're really looking to avoid it the Scandi's your best bet against e4
Xx