I want to progress

Hello everyone !!!
I know his subjects are very common but
I would like to ask how to become more "stable" in my performance ect ... for a while I have been feeling behind in bullets and blitzes and sometimes i point with disastrous / better performance changes but i do better less often only disastrous results: (and I don't like to stagnate at the same level. and it is quite frustrating. my blitz ranking is a real roller coaster and I am a little disappointed that my level stagnates at 1750 and that I do not arrive not at 1800 and in the bullet it is even worse. I also feel that I am bored in the classic and I would like to find it as attractive as the blitz and the bullet, I know there is surely different particular tactics for each game mode. But I'm making less progress lately and I really need some advice. Is it bad luck? Overly original tactics? Or my opening repertoire which is original? I will try to listen carefully to all of your advice.
don't panic, I never despair !!! I just want to progress
I thank you in advance !!!

@CSKA_Moscou Blitz improvement comes with rapid and classical improvement. If you play more rapid and classical, analyze your games (With your brain, a stronger player, and lastly Stockfish) you will improve a lot. You will have time ot watch for both strategy and tactics. Puzzles (Regular and Streak) can help here. Playing exclusively blitz over and over aimlessly will not help you. Blitz is all about pattern recognition and inuition, as well as solid tactics. Puzzle Storm and Racer, having a fast mouse, and playing only when you are focused and "in the zone" should help. But just remember, the fastest path to improvement is rapid and classical first. It may be boring, but that's how you improve. It takes diligence and discipline.

Play longer time controls
Practice tactics and endgames
Don't study openings deeply until you reach GM level
Once you reach 1700 in lichess rapid you can add positional chess to your curriculum

I find it interesting to actually be able to think about my moves (instead of just blitzing them off in kneejerk fashion).

Play lots of correspondence, rapid and classical. They will give you more time.

#4 @MrPushwood well you would know the only rated games you've played in corrsepondence lol

that's telling me!