I also have the habit of blitzing out moves out sheer impatience and a lack of discipline.
I too am in the 1400’s.
I arrogantly started my account at 1600, won some games, and then got pushed down into my current rating.
So from my perspective you aren’t all that special for your rating, it’s just that people in this rating range are pretty serious about chess in general.
I too have a “vast knowledge” the problem is that if you can’t consistently call upon all of that accumulated knowledge when you need it the most, it isn’t all that helpful in-game.
That’s why we must make an effort to apply this knowledge whenever the opportunity arises, until it eventually becomes habitual and intuitive.
Good luck in your further chess improvement. :)
I am 18 years old and have been playing chess for one year. I feel I have a vast knowledge of chess understanding in comparison to my opponent's(watched plenty of instructional ichess.net videos and played through World Champion and Super GM's games from all time periods dating back to the 1800's with Paul Morphy) In addition I played through top engines games of Alpha Zero, Leela, Komodo, Stockfish, Stockfish NNUE, Winter, etc. Since it's summer I have plenty of time on my hands to study and play chess. Honestly I feel it is too early to claim to be "stuck" because it has only been about 1 month that I've been 1400+. As you could see from my profile, I am better at slower time formats and I feel the best games I have played have been against engines where I could sit and think for hours before making a move. I feel that I am not the typical 1400, I beat chess.com's 2000 rated engine, beat Play Magnus age 10, and beat Lichess.org's Stockfish lvl 5. Before I was playing to slow and blundering because I was in serious time trouble despite being in a better position on the board, now I find myself blitzing out moves too fast...or at least lacking the discipline to check the meaning behind ALL of my opponent's moves. I am not interested in cheap tricks or opening traps to boost my rating 1500. I feel I will likely reach it before summer ends but it would help if I had some external wisdom and guidance to help me get there faster and not go through the grueling trial and error process of coming up with new conclusions and philosophies on what I need to do to improve and patch up the gaping holes in my games. It would help if you looked at one or 2 of my games to see exactly what I did wrong and bad habits I have, because like i said before i don't feel as though i am the typical 1400 rated player. Thank you for taking the time to read this and providing me with your wisdom and feedback.❤ btw for right now i am only playing 15|10 in Rapid