Urgent?

I’ve just started uni against medical advice from my eating disorder therapy team. I have a diagnosis of anorexia and this is my third time at University (having had to drop out previously). I’ve been really struggling so far with my intake and exercise etc and it’s starting to affect me physically. I have no energy at all (I’m currently in bed rather than a lecture), awful leg cramps, I feel dizzy and faint a lot and occasionally have chest pain (it was bad last night). I have a GP appointment for next Thursday but I don’t know if I can wait that long feeling like this. I don’t no if I should call them today and try and get an urgent appointment to speak to someone this afternoon or weather that will just be wasting their time?!