I have been wanting to try HBOT for at least 3 yrs now but the cost here is much higher than where you are. It's a minimum of $110.00 per session and the doc that runs the place said that I would have to go for a minimum of 40 sessions but feels that it may take 80 or more sessions. They would do 2 sessions each day. Plus I would have to travel about 6 hours to get there and hotel costs would make my total bill near $10,000.00 more or less.
I don't know how far you would have to travel but I say give it a try for £10 per session.
I too have heard mixed outcomes with HBOT and RSD. But with it being non-invasive, non-chemical... if I could afford it I would definitely give it a try.
Best of luck to you Ali and Andrea!!
My fingers are crossed and you are in my prayers!!!

Abbie