Glad you are seeing the rheumatologist. Sorry about all the pain. Clearly, you think for yourself and work through these issues.
I would think that physical therapy would not decrease inflammation - it's purpose, as far as I have read, is to do just what it did do for you - help with flexibility and posture.
Epidural steroids may help anyone who has any kind of inflammatory condition of the spine, I do not think a good result is diagnostic of AS. Hope you get one