Crying because of physics

I don't take physics but I used to get incredibly frustrated with Maths to the point to where I wanted to cry as well. This might sound harsh but what is probably happening, speaking from experience, is that you basically don't understand the content because your fundamental understanding of the topics are weak, hence why you are struggling with the A level. I'll give an example with maths, if you don't understand the logic of how solving a quadratic works( setting to zero, factorizing, crosses x axis is solution) for example, you will struggle with basically the whole A level. This is what happened to me and why I struggled with maths in the beginning, my advice is to start from the basics really, even if you have to go back to gcse content. Alternatively, if you don't want to that you can just drop the subject and pick up a conceptually less difficult subject, this will result in finishing your a levels a bit later.