Approaching Later Exams

Hi, I study maths physics and chemistry. I've got an offer for AAB, the As in maths and physics, but I'm incredibly unhappy with how my first physics paper went (OCR A), and while paper two was much nicer, the grade boundaries will obviously be higher. I'm worried I'm averaging out at a B at the moment, I might be pessimistic, but this is eating at me. I've got my first chemistry paper on Monday, then Pure and Stats on Tuesday, I know I need to focus on those two, but I don't know whether I should put more focus on preparing for the Physics Unified or treat my subjects equally. I need to deliver in the Unified, but I can't afford to jeopardise my other grades. Any advice would be appreciated, ideally from people in a similar situation or people who've been through it.