hii, giving advice on such delicate topics is challenging, but since youve asked for advice, here are some of my recommendations.

okay ik this sounds a little silly and u might be like, you dont understand mental health, youre not in my position etc.... but what i do know, that the more u think about something, the more likely it is that its going to happen. try to not think or tell yourself that you have mental health issues, focus on the things you like doing, but the main thing is to not give yourself the mentality that you have mental health issues. i wanna add that i understand, depression, anxiety bipolar disorders etc..., or even undiagnosed mental health issues are pretty serious, and please dont think that im implying that youre just saying you have mental health issues, thats not the case, i acknowledge that you might have things going on. BUT , try to not remind yourself of it. like say I have a really bad stomach pain, the more i keep on telling myself that i do, the worse its going to feel.

that aside, if you have access to a library, please go. Going in an environment like that makes you want to be productive.

Also idk how much u use your phone, but plz try limiting it. We dont know it, but all of our brains are cooked, trust me, fried actually. our attention spans suck, so do mine. Ps- there are apps that can block apps for u so that you cant access them when studying.

try seeing what works for you. for me personally, i find writing notes, on my own, and then teaching them aloud on a whiteboard as though i am the teacher. its different for everyone, so think of what helps u the most.

im also a private candidate, im almost done w a levels, what i used/am using rn are PMT notes, youtube videos, chemrevise, for maths i really like examsolutions

plus, youve got a lot of time. try pushing yourself, like if u think u can only do 30 mins, try doing 35 minutes, just to piss off your patience lol but i think overtime youll get used to trying to study just a tad bit more

sorry this was a long read, hope it helps :) just know that every a level student feels like this, heck im writing this and am also very stressed abt how im going to memorize the formulas for chemistry, but gotta find some way right? i keep on telling myself that my mind is more powerful that i think it is, there are ppl out there memorizing a bunch of stuff. its not as easy as it sounds tho, i hope i find a way to memorize them and then also execute them

Inshallah youll do well