at my peak in 2011 I managed 1800 bullet (chess.com/chrisr4). today I am litarally half that rating. it is extremely discouraging, i feel lost playing chess. I don't know where to begin to improve and i just feel shame losing at this elo
Bullet can be pretty brutal. Maybe play some slower games while you find your feet again and get back to speed? I doubt all that knowledge and instinct just went POOF. It's just hiding, and you gotta coax it out.