Miserable and making no progress with A Levels?

I'm stuck and I really don't know what to do.

I'm currently in Year 12 studying Biology, Chemistry and Geology at a sixth form college, and no matter how hard I work I'm not making any progress with my subjects and I just keep failing? GCSEs for me were fine and i did well, but no matter what I try for these subjects I just fail every exam - I think it's because I'm struggling to remember the amount of content and the fact that the exams are more applied learning? My head just doesn't seem to work in that way.

I'm genuinely dedicating all of my time to trying to pass because I was really hopeful of studying Zoology at university, but for that I need 3 A's. That's been something I've always wanted to do, but now it just seems like regardless of the effort I'm putting in and how hard I'm willing to try, I'm just not going to get there.

What are my options? Do I have any? I'm genuinely so miserable nowadays with all of this and I really don't know what to do. I have 3 mocks all on Monday and I've been so busy trying to catch up (I was off college for 3 weeks with Quinsy back in February) that I don't have time to revise, and then after that my real exams start.

Part of me wants to drop out at the soonest chance I get because I'm so stressed and miserable now, and the other part of me hates the fact that if I do, I won't be able to do the course I want in university, which also makes me so upset to think about because of how hard I've been working these past few years.

I really don't know what to do