Had another thought
I had tried 10mg Amitriptyline for pain relief before, and had to stop because I got so brain dead.
Swore I would never use them again.
However, headaches and other pain became tedious, so I had another go.
The brain fog / death was much less this time, but did strike with vengeance after 2 weeks.
So that, in connection with the fact that the pain wasn't sorted, has meant I've given up again.
I'll try Gabapentin next to try and stop pain, might work...............