If I had an a* in RE I'd do that as a fourth a level to balance things out a bit. Maths is a good core subject.
I've read you need maths as it's a tool for writing with.
I think if you want to go down the science route seriously you need maths.
RE still might be a good a level to balance your views out with.
I'm not really in the science field. I'm doing history and I specialise in architectural history. I find science fascinating from a historical point of view.
I hope you find the right course for you and as you've got at least a year you should spend some time finding out what you want to do at university.
Good luck.
Oh and there's a meteor shower starting on 22nd April so look to the stars you might see your future up there.