Need some advice.

I’m starting my A levels in september and i feel so underprepared and overwhelmed.

The subjects i’m doing are Maths, Physics and History and I need to get awfully difficult results of A*AA to get into the university cause of my desire.

I have a dire interest in physics and very much enjoy history but maths is the one i’m most concerned about.

Does anyone have any advice to prepare myself for the probably struggle?

Thank you in advance.