im completely cooked for chemistry

im in year 12 and i feel sooooo lost in a level chemistry. i'm aiming for a B next summer but its not looking good at the moment. my teacher isnt the greatest and i genuinely feel like any time i revise, nothing goes into my head. when i look at past papers i feel like jumping off a cliff because i KNOW if it was me sitting that exam, i'd skip most of those questions because there's no way id know the answers.
someone help me because i cant keep teaching myself things from that textbook i'll literally combust.

Heyoo! I'm in year 12 as well and wouldn't say that I'm doing well in chemistry, as it is absolutely brutal at times, but oh well. May I ask what exam board you're taking and if you're in 6th form or not?
In terms of chemistry in your lessons, The first thing I would suggest to do is find others in your class who are achieving good grades in chemistry and asking them, not necessarily for their notes or flashcards, but for them to simply explain a concept to you or perhaps a 3 or 4 marker question. This not only will benefit you but it also benefits them; they increase their understanding of the topic themselves by being able to teach you a part of it! Sadly there's not much you can do which isn't extreme with a bad teacher, but if others are getting through it then you can too!
Another suggestion, more to do with past papers this time, is to ease your way into them. I tried jumping in and regret it now, as my time management is all over the place and I'm very similar and skip all the 3+ markers and leave them to the end!!! I suggest starting with like 1-2 full questions a session of revision (max marks for each about 10 you can just find them from a past paper you haven't or even have done if you don't remember it fully). I know it's constantly overstated, but a reward at the end of a study session is soooooooo good! I'm a bit of a gamer myself, so I always look forward to an evening game or watching a load of anime; this big reward after all the revision! Besides the point, I heavily suggest having a good 20 min break every hour or so (experiment with this everyone's differnt I'm a little crazy with my breaks!) where you can do something you ENJOY, not some 2 min breathing exercises. If they're for you fine. But if not maybe get some fresh air in the garden, message some friends, or maybe even have a little catchup with family and tell them your study plans so they can hold you accountable! Ok maybe that last one is pushing it a bit too far... 😂
Apologies if this is a whole 500 words of yapping, it's 1:00am currently and I've had a couple of late ones, so my brain is slowly losing it! But I really hope you find this helpful, and if you need any more help whatsoever, please feel free to mention, Private Message, or even @ me in another thread! I'll try help wherever I can