One thing I have found that has helped me immensely is aqua therapy and warm water aerobics. I have RSD/CRPS that causes severe pain in my entire upper body. I also have Sjogren's Syndrome, which causes arthritic symptoms primarily in my knees and hips. I am able to do things in water that I could never dream of doing on land. And while you are in the water you are practically weightless so your size doesn't matter. (I too am overweight.) My neurologist ordered the aqua therapy 8 weeks ago for the RSD/CRPS. I have regained a lot of the strength I had lost and increased the range of motion in my shoulders (which were both partially frozen). After 6 weeks of aqua therapy, and with my doctor's permission, I started the water aerobics. The pool is kept between 91-93 degrees F. While I am in the pool my pain is at a minimum. So far I have lost 10 lbs, gone down a full size, and I feel so much better mentally. It is something you might discuss with your own doctor and see if it is an option for you.
Cricket