One big, warm, tight, hug, handshake and howdy, moose-size welcome to the site.
This place is amazing!
I'm so sorry for the pain you're in and hope you and the docs can find a remedy soon. Odd that the heat helps. I was stationed in England many years ago so I'm familiar with your weather. I live in North Carolina now. HEAT! And lots of it.

Would a heating pad or even hot water bottle across your back in bed help at all?
So don't be scared anymore;
You are not alone.
You are one of us.
And we are here to help.