y13 maths advice

heyyy ive just started year 13 and i study econ, french, Spanish and maths. in my mock i got a low b in maths and my teacher said she will predict me an a (since i need it for uni) but im wondering whether this will actually be feasible since i sometimes struggle to keep up with the topics. over the summer i consolidated a lot of the work and i actually was able to understand everything i previously hadnt. honestly it might be an issue with time and i tend to get very upset with myself when i dont understand something and it usually stacks up very quickly.
this v=being considered - will i be able to stay on top of the topics or will oi not quite hit the a i need?