NEED HELP TO BREAK OUT OF 800 ELO

ive been playing chess for years but i mainly keep losing idk why . but recently after studiying some chess openings like ponziani for white and caro-kann for black , after studiying em ive recently been winning some matches and have the confidence back to learn more . ive choked at 800 elo like 4-5 times here before . i need help to get past this elo .

you can go checkout my last few matches and pls point out any flaws i have that i should work on . 

ive done a few free courses off Chessable and have learnt some from a local players who are experienced . please give your advices and thoughts on the comments / forum id be more than happy to read 

Learn and apply the most important principles of chess. - (core of my teaching)
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.

The thing that broke me out of the 8-900 range was 1. Blunder checking and 2. Always look for a better move. Blunder checking is something that people forget to do, especially when we start playing faster time controls. Always look for captures, checks on both your king and opponents king, attacks where you can get either more than one piece attacking a piece, or a heavily defended piece attacking an opponents piece. Attack their queen whenever you can with your defended pieces and try to get it off the board. Looking for a better move will become easier in time. When I'm playing 10mins or more games, I look for a move, and then scan the board again looking for a secondary move that might be better than the first one I found. For me 7-10times there's a move that I missed that's much better than what I was going to do originally. Also... Don't practice your opening as much as practicing how to play against a bunch of different openings, knowing the top opening moves of the Scandinavian, the London, the Italian, the Scotch and other popular openings by both white and black. It will help with vision and knowing the proper way to move forward into the middle game. Hope this helps.

Improving Your Chess - Resources for Beginners and Beyond.....

https://www.chess.com/blog/RussBell/improving-your-chess-resources-for-beginners-and-beyond