I'm in the same situation and I'm not sure if I want to carry on next year in sixth form, I feel like I have no time anymore and I feel that I would enjoy my subjects more if there wasn't the pressure of examinations there.
My advice would be to try as hard as you can for the moment(that's what I'm doing even though I have not motivation).
Also, go on uni websites and check the entry requirements for the course you want to do (if ur still interested in uni) and see if maybe BTECS are an option. I'm in a very similar situation and I'm struggling to do biology, psychology and sociology. I want to do nursing so I'm thinking of doing a level here extended diploma in health and social care (same ucas points as 3 A levels) for 2.5 days a week. Or I think I might do psychology and/or health and social with applied science as well an an EPQ dissertation which I don't give up (I think I want to keep psychology as it's the only subject I like)
I would say to speak to your careers mentor if you have one and maybe speak to the head of sixth form or a leading member of staff to see if they can help you find better courses. I would have one year of sixth form left but I would rather do a two year course that I enjoy rather than courses that stress me out too much.
I hope everything works out for you, DM if you need anymore advice 🙂🙂