Hi Fluffy Dinosaur, welcome to PC. I hope you are able to find this forum helpful. Obviously, we aren't experts, but there are many here with years of helpful experience.

I am admittedly a bit out of my depth, but I was wondering if a diagnosis of Schizoaffextive Disorder Bipolar Type has ever come up with your doctor. Isolation can be a symptom and it would also explain the euphoria and psychosis.

Keep in mind that you're on a spectrum somewhere. Any one diagnosis may not be a perfect fit. I'm floating without a proper diagnosis myself. It feels uncomfortable not to know exactly what is causing your discomfort, but the most important thing is to ensure your symptoms are being addressed. The treatment plans for many of these disorders overlap, so perhaps you can find something effective while you and your doctor are waiting for things to play out.

Good luck to you. It is nice to have you posting and I hope you get the answers you seek soon.