It does seem like you've decided to take Maths, Further Maths, Physics and Chemistry, which I can totally appreciate because that's what I do (I'm Year 12)
I would just add that if you have an interest in biology there's nothing to stop you pursuing the parts you enjoy, in fact many people say that's the best way to appreciate science, as opposed to studying a fixed curriculum.
Saying all this, Further Maths is easier to self teach than Biology, a friend of mine has done just that (I can't confirm that he's done it well, we'll have to see what grade he comes out with)