HI again! I've been reading your profile and can relate to it. I also had intense back pain before the surgery. I was injured at work and could hardly walk, much less exercise. This is where I gained most of my weight, and in fact became handicap. Even though you have disk damage, simply carrying less weight on your frame may decrease your pain - as it did with me. As I began to lose weight, I had less pain and was eventually able to exercise. It's worked so well, that I no longer and handicapped. In fact, I took great joy in tossing my old handicap sticker into the garbage!
I hope everything goes well with you - drop me a line if you need anyone to talk to!