Without doubt the single most unedifying experience of my life. I was a emotional mess before during and after it, I didn’t sleep for weeks.
try and take someone with you if possible and please please do not fill the forms in alone. If you have a specialist who deals with pip forms locally contact them, citizens advice etc. Also lots of great advice here re: doctors historic records. 100% get copies and highlighted them. Make sure there is no conflicting comments or anything that suggests you are healthy, recovering or “ not as your condition reflects”.
ill say a prayer for you, and best of luck, keep in touch and let us know how it goes.