Should I change my opening ?

I have changed my opening many times for white :

1. My first coach always played the Sicilian and I was prepared for that with the Alapin

2. But then, a player played e5 when I played e4 and I actually didn't know how to play against it

3. I learned to play the Center Game

4. I began losing many games when I reached 1250 so I had to switch my opening again

5. Switched to the Italian, I loved to play the Fried Liver but when I reached 1325 many people did not fall for the Fried Liver and ended up losing and to be honest, I found it a bit difficult but then I won a few games with the Fried Liver and reached 1375

6. I switched to the Scotch Harry Potter variation and I reached 1500 with that opening

7. Should I switch to the Italian Giuoco Pianissimo because I currently think its very aggressive.         In fact, I beat the GothamChess bot with that opening, Have a look at it :-

https://www.chess.com/game/computer/1412297

What do you think? Is the opening really so strong? Or was it because of the middlegame/endgame play?

You could switch from the Italian to the Ruy Lopez. The two openings are very different, but I've read experiences in which the Ruy Lopez can help you get over that rating hump, since players at your level can handle the Italian well. 

Actually, I've never played the Ruy Lopez and I will need a lot of practice. Maybe I'll practice playing the Spanish in a few unrated games on Lichess

I think the Italian Game is also good, as there has recently been some high profile games. Knowing the deeper ideas could help you a lot. 

Every time you change openings you lose more, not less. So it is better to stay with the same opening. Just play it all the time against all opponents and all time controls and you will gain experience with it.

If you dont want to learn a lot of theory you might like to try the 4 knights. I started playing it recently and so far I find you can just play common sense moves and get a decent positon.

I didn't really 'practice' the Ruy Lopez, and I didn't really practice any other opening I currently play. I just played them. If you are going to practice openings, do it in rated, where people take the game seriously.

I take unrated games seriously as well because a loss is a loss

Well, other people often don't take it seriously.

Many players on this site dont take rated games very seriously either.

Maybe I should make a speedrun account and check the rating I can reach

Have you ever given the Vienna a try? 2.Nc3

The London  system is also a good choice 

You know I hate 1. d4

Danish gambit ?

How come?

Tip for openings: NEVER play 1. a4, 1. h4. 1. a4 2. h4 or vice versa or pretty much any opening that doesn't take the center

They are the worst openings

I never play those