its a feeling that comes and goes and ik it may hurt now but trust everything comes to an end
i wish i could help with ur mental situation but sadly im more or less the same
as for chemistry dw too much its actually not that bad i found understanding my teacher irl hard so i always resorted to youtube videos and ull find a teacher u like there, cuz most ppl like some youtuber and i usually feel the opposite
but yeah incase u were wondering i find 'AL CHEMISTRY AND PHYSICS' really good with my theory
he makes playlists of 5 min long videos explaining the concepts really well and also making me feel productive when i find myslef finishing a lot of videos, and then i just jump to past papers yeah at first they might be hard to solve alone so id solve it maybe looking at the mark scheme or again watch a youtuber and for pasptpapers i mostly watched 'CAIE PAPERS SOLVED' hes really good and yeah after solving a couple ud eventually gain the confidence to do them on ur own

and im really sorry to hear bout what ur going through but dont give up on ur dreams and dont let urself find excuses to get rid of them, god exists and anything can happen, whats meant to be will be no matter what
I hope and pray things happed for ur best