Retake Year 12 for new subjects?

I’ve just started Year 12, and I’m currently studying Maths, English Literature, Psychology, and Russian (which I’m doing privately). However, I really dislike Psychology.
I did Psychology at GCSE and did decently, but I started disliking it in Year 11. The only reason I’m taking it now is that some universities consider Psychology a science-based subject, which I thought might open up more options for me.
During the first week of Year 12, I had a lot of anxiety about my A-Level choices and what I want to do at university. Because of this, I switched sixth forms and took Maths, Physics, and Biology, which I enjoyed more. But again, I doubted myself and went back to my current sixth form. The issue is that at my current school, I just barely missed the grade requirements for any science subjects. However, at other sixth forms or colleges, I comfortably met the requirements.
I’ve thought about switching sixth forms again, but I considered changing schools about five times in that first week alone, and now it feels too late. My parents are also frustrated with my indecision, and it feels like I’ve run out of time to join a new school.
My true passion lies in studying something STEM-based at university, like Computer Science, Astrophysics, Aeronautical Engineering or Earth science. However, the only way I could pursue these subjects now would be through a foundation year, which I’ve considered but would rather avoid.
My main question is: Should I retake Year 12 and study Maths, Physics, and English Literature at a new school, so that my options are better aligned with my interests? Or should I continue with my current subjects and consider a foundation year or other degree options?
Please let me know if I have any other options in regards to this!!