Psychology, Sociology, Maths and Further Maths?

They go great together, thought that was common knowledge.

that's what I thought but my teachers are making me think otherwise.

Because they are dumb. Psychology is about the individual, basically dispositional analysis. Sociology is about groups and the external variable that effect the behaviours in question. When they both look for answers in the questions they ask, they will attribute the cause either dispositionally (Psychology) or externally (Sociology). This would cause what is known as a attributional error, and both aspects could attribute to the behaviours they are seeing. Both subjects works along each other, it is stupid to think otherwise.

Makes sense, thank you. What about unis, what do they generally think about doing both of them at A-level?

Doing them both at A-level is fine, now degree choices is another question. You can either do straight psychology or perhaps social psychology and sociology. But I find with the latter it is more sociology and psychology on the side, so major/minor if you like. Perhaps you might find you like criminology, and take psychology as an secondary as well. Really depends where you want to be career wise.

What about if I want to do law? I'm not good at writing at all and so I didn't choosing essay based subjects like English Lit or Government and Politics although I know you need them to do law tbh. But I'm good at psychology and sociology because the essays that we have to write are memorised content and I have no problem writing essays if I'm just copying down stuff that we learn and I don't actually have to write something spontaneous if ygm? I'm not sure what I wanna do yet all I know is I probably wanna do law or accounting :/

In that case, a degree in law then, not entirely if you can do something else with it.