Why do I suck at chess?

I suck at openings but l’am really good at end game

you need practice young jedi not everyone start out as a master jedi

Yeah, really good.

In this endgame, you were completely winning (obviously, as you were up 2 pieces), and you agreed to a draw. (???)

https://www.chess.com/game/live/141387666097?username=just-maybe

Because you blunder your pieces too much!!

Because over half of the time you are playing a computer.

Yeah i do tend to blunder a lot

Learn exactly how to think in the opening, middlegame and endgame — this is what I teach.
Always blunder-check your moves.
Solve tactics in the right way.
Analyze your games.
Study games of strong players.
Learn how to be more psychologically resilient.
Work on your time management skills.
Get a coach if you can.