Long story short. (Isn't it always)
What spurred on the process of me being referred for diagnosis was what I found out in retrospect to be a severe shutdown.
I just ceased to function and fell into a catatonic state for over 2 hours.
But curiously. Afterwards. A lot of my personality changed because of this. My likes and dislikes in food, tv music etc. It all changed. Even my hayfever disappeared. I now can't write properly either.
Which makes me think that, at the neurological level, changes were made in my brain.
I wonder if anyone else has experienced or heard of such a thing?