Hi. I’m afraid I don’t do either physics or biology, but I do maths and chemistry. I find maths rather difficult, but I averaged 6s and an occasional 7. If you average 8/9 you should be fine. Chemistry is really good fun, a lot of it is building on old stuff, with a lot of new stuff as well. From what I’ve heard from my physics friends, there is a lot of maths so you should enjoy it. I think in the first year, they learn about mechanics, electricity and waves, not 100% sure though.
Make sure you choose subjects you enjoy, as if you enjoy it, you’ll find doing work is easier (trust me in this)
A levels are hard, they’re meant to be. I don’t think I’ve met someone whose said they think they’re easy. Just try your best, and do what you enjoy. It’s all any of us can do