Private diagnosis to GP shared care - Somerset?

Hi guys

I'm getting myself so confused about what my next steps are.

I have been privately diagnosed via ADHD Certify, and my GP in Dorset has flatly refused shared care - he said all of Dorset is the same, thanks to a new policy coming into play.

My parents live in Somerset, is it worth seeing if anyone in Somerset will accept shared care??

I keep reading about Right to Choose and I don't understand how that differs from being on the NHS waiting list....

I'm just in such a muddle - can anyone explain my options?!