Need help

I'm currently in lower sixth and doing Maths, Physics and 3D design. I'm hoping for AAA* respectively. I've realized I want to do a physics degree, and so I've been thinking about doing as further maths in upper sixth. I want to know if it's worth it and if it will help and I know that some people have said it makes it easier to achieve a A in regular maths. Should I give it a go?

Have a loook at the subject requirements of the unis you are considring.
Will you school allow you to start A level FM now?

It would be a As in further maths rather than a full alevel. I was just wondering if it would help me?