I shall be thinking of you when you go for your appointment, ethelt. Perhaps you should make a list of the questions you want to ask, as from experience I know your mind will go blank if you rely on memory! Don't forget that the majority of the comments on here on your condition have been encouraging as to the outcome. Let us know how it goes.
The difference between Wealth Tax, Inheritance Tax and Income Tax
Retiring and living frugally in money from downsizing after years of stress
There will likely be a nurse there to explain to you about the treatment, they understand your fears and will help. Ask for help, don't bottle it up, and offload on here anytime you like, there are lots of people who can empathise and help and advise from experience.