In three years I reached 2400, I don't know how it turned out, just learn from mistakes
how should i get better at bughouse?

Have you looked at all the guides and blogs in the info section of this bughouse club? Have you bought the two bughouse books and done all the mate puzzles? Do you go over your games afterward to look for better moves? Do you play with partners on voice and listen to their suggestions? Do you watch top level players play?

Amazing Bughouse Tactics for Kids...and Adults! (2014) by David M Chong
Bughouse Chess: Tandem - Chess / Team - Chess / Exchange - Chess / Hungarian - Chess (2006) by Georg Von Zimmermann (Editor)

Bughouse is a very tactical game and you can practise bughouse tactics by doing puzzles on this website: https://bughouse.ca/
(disclaimer: I'm one of the developpers of this website)
i keep staying around 1800-1850 rating. Thanks!