What should I take for A-Levels?

I'm thinking of going into Astronomy/ Astrophysics/ Physics, anything to do with physics really as I find it really interesting, but I don't know what subjects I should take in Sixth Form before University.
I know I have to take Physics and Maths, and I'm already really excited to be taking those subjects, but the Further Maths is only a Level 3 and not an AS or A2, so I don't see the entire point in taking it as the university I'm wanting to go to, and the course I'm wanting to take, doesn't take A-Level equivalents.
I am taking Criminology, as I find the subject interesting, but I may drop it in the first few weeks if the work is too much (as I'd be taking 4 A-Levels, it should be fine though), but I know I should probably take Chemistry as well.
The only problem is, Chemistry is my weaker science, I recently became home-schooled and my mum decided to have some of my exams in January, but the new home-schooling course is on a new exam board so I've had just over half a year to do two years of a whole Chemistry GCSE course. I don't think I'm going to do that well, with a high C- to high B. Another problem is I went to the college that I will be going to for Sixth Form, and I met the Chemistry teacher there, and he just seemed frustrating the whole time. He's unlike any teacher I'd ever had before and made it seem as if science wouldn't be my strong suit (although this could be down to sexism I don't know). I don't think I'd be able to take a whole two year course with him.
So, I just want to know if there are any other subjects you think I should take, or if you think I should just stick through Chemistry.
Thank you for helping me out.