After a long and hard think, I'm going to chat to the doctor about this. Been reading about it on and off for a year, and I think I'm at a point where I do need to pursue this. It would so explain why I go off of the rails at a change in routine (illness), why I'm so anxious about my course (no routine whatsoever) and why my mental health has been so shocking for years.
Maybe it won't add anything to my life, but it might help me understand myself a bit better.