I'm autistic and I passed my test in a manual last month, in my40s.
I chose a very calm driving instructor and warned him I had extreme social anxiety and would probably be very, very nervous. So he took it slowly and NEVER got wound up at me.
We started in the quiet end of a supermarket car park, on the quietest part of the week, just going up and down to get used to the idea and to concentrate on getting the hang of coordinating feet/hands etc. We didn't hit an actual road for a month. He regularly took over doing the indicators if I needed to concentrate more. Crucially, he stayed calm!
I found two hour lessons with a toilet/coffee break in the middle was best. You spend the first bit calming down (we always started on the same easy route to get into it again), then the second half doing harder stuff once you're calm.
Honestly, it was fine. Way better than I'd expected. I passed first time despite having shit coordination!
If you're in the NE I can recommend him