Best of luck Tidaldestruction with everything you are going through.
My brother has both a severe case of ME and fibromyalgia. He has been ill for some years now and when he first became ill it is true to say that ME wasn't always accepted as a diagnosis but was seen as a cop out and something not real.
He has been put through some weird and wonderful treatments none of which worked including the "go back to work it is all in your mind" one which set him back very badly.
Lately he has been seen by a consultant who is having great success with seratonin and the gradual increase over a long time method. He has seen improvements although at first he took a step back , it isn't a quick fix by any means but the improvements he has made make my brother feel so much more human.
Tidaldestruction I truly wish you all the luck and hope that the Tumour is successfully removed.