Really depressed.... what's wrong with me...

I don't know why do I always end up doing something wrong... I am a partial dropper from dtu... this time everything went right with mains, still don't know why did I mess it up, gave around 20 mocks in Jan and December... gained a mastery over time management (did it well in paper too), but somehow I messed up chemistry in my paper... I got 98.1 overall in mains 1, with 99.7 in phy, 93 in chem and 96 in maths... maths I know I still do decent (got more in my mocks but I gave less time to maths in paper due to physics so that's satisfiable) but chem??? Man I literally did 8 questions wrong in a straight line... like even the board questions too... have an avg score of 65-75 in my mocks but this time so many stupid mistakes I did that put me to 40s, while last year I got 80 marks in chem with 98.9 in it (literally while checking response sheet my hands shivered as I was like wtf did I tick this option, this was so obvious, even before checking the answer)... now I have moved on to advanced prep (yes now I should) but still I want a good score in mains 2, but now I am really underconfident, cause now I feel that yes I will maintain good in chem this time but will mess up physics for sure (I am stupid man)... what shall I do now? God why did this happen to me, I never scored so less in chem, even the paper was easy yet... if u guys want to guide pls do so... I want atleast 99.2 in mains 2nd attempt... pls god please....

Target : 99.2 in mains 2, under 6k in advanced, with more focus on adv practice while giving mains mocks regularly (and adv mocks every 2 weeks)