1400 rating in 4 months, how do I get higher up?

Hello! (This is not my account in case anybody gets confused)

I have been registered on this site for about a year, but I just recently started playing chess on a regular basis. I had about 10 played games 4 months ago (blitz), but sometime in May I decided to start playing chess and became really interested in it. When I first started off, I have absolutely NO knowledge of chess and quickly my rating dropped to around 950. I stayed there for a few days until I got up to 1000, and a few weeks later I was on 1100. Sometime in July I reached a 1200 rating, in August a 1300 and now I'm on a 1400 rating.

I have done all of this with no studying so far (except for learning the only opening I know, the d4 opening for white). Also I have played quite a lot (about 2000 - 3 minute blitz games and a few 5-10 min games). I have about just as many wins as losses and it feels like it will be harder to improve rating-wise from now. I am stuck at around 1350-1400 (even though I often beat people around 1500, and even won a 1900 guy in an unrated game) but it feels like it'll be hard to improve.

I have tried some tactical solving but I feel like that isn't what I need to improve, I'd say my tactical skills are pretty good as well as seeing traps etc. I might be wrong though, so I'm curious, what should I study, and how/where? It feels like I'm at a point where I cannot get much further unless I pick a book or something similar up. I have tried a book but they're so boring with these endless made-up positions and all these notations...it feels like I'm not gonna get anything out of it. And what openings should I use for black? I pretty much improvise the black-opening everytime I play. Sorry this is my first threat here hope you guys understand, thanks in advance!

EDIT: In case anybody would like to see some of my games, I can write down the notations here!

The best way for you to learn is to be able to find your mistakes and then to be able to understand and correct your mistakes.

Are you now able to find your mistakes?

If you're less than 2000 chances are most of your games are being decided on tactics, or players just dropping pieces. I would say just do tactical puzzles, if you change your mind about chess books I would recommend Yasser Seirawan's Winning Chess Strategy as a good starting point for strategy, it was the first chess book I ever read and i felt it helped quite a bit

Thanks I will try to look into puzzles once more

There are 2 ways you can improve.  The first is by studying which will give you more to think about and the second is to play slower time controls which will give you more time to think.  Don't like books?  Plenty of video presentations, much of it free on all phases of the game.  Chess.com has a youtube channel with a whole bunch of relative beginner type videos that might help.  Eventually you're going to need to start playing longer time controls though and start analyzing your games so you won't keep making the same mistakes.  1400 in 4 months with no study definitely shows potential though.  If you get serious about improving think about bumping your membership up to diamond and tackle the Chess Mentor.  Much more efficient use of your time than books IMHO.  I know you wrote that you seem to be OK with tactics but tactics are like the vocabulary of chess and they're almost universally recommended as the quickest way to improve.  Good luck with the Game.

Thank you! I will definitely try to look into tactics again, but, if I am to start playing longer time controls, which ones would you recommend? 10-15mins? Because I am going to go to a tourney just to try it out, (time controls 1hr) and the players are going to be around 1500-2000 rated, so I guess playing longer games should do good. But, how long games should I play?

If you hadn't said you were going to a tournament I would have said 15/10 since that's a significant bump up from blitz but since you're going to a tournament with 1 hour time then logically that's what you should play.  The Dan Heisman Learning Center is a group of a few thousand members that play long time controls and have tournaments.  Joining is probably the easiest way to find others who want to play long time controls.  Since you're just "winging" your openings at the moment It wouldn't be a bad idea to try some turn based (correspondence, online) chess.  Gives you a chance to really think about your moves and more importantly it's "training wheels" chess where you can use opening books and databases to get you through the opening and into the early middle game.  Tournament players usually know their openings pretty well so it would be a good idea to be able to go "book"  for at least the first 5 or 6 moves.  Check out the study plans on site too; you won't have access to everything they recommend you study but it's a place to start (listed under "learn" in the green ribbon bar).  As usual I've shot my mouth off way too much... Good luck.

1400 guys just seem to smash me on 30 minute games, I'm around 1250-1300 there it seems