health problems: arthritis vs. bariatric surgery

I have a health dilemma. I have bad arthritis in my back and my doctor is pushing weight loss as the solution. She has recommended weight loss surgery, which I really don't want to have but want the benefits it offers, like losing weight to finally be treated by doctors instead of being told to lose weight. But I know there is a chance my back will still hurt after the weight loss surgery and I know there is a chance of regain even after the surgery. I just want to be fat, happy, and able to walk or get around. Buying a scooter is not an option as I am on disability and I can't afford one, and I doubt my doctor would fill out paperwork for me to get one from my health insurance. I am in physical therapy now and everyone keeps telling me "use it or lose it" but I am in so much pain sometimes I want to just overdose on tylenol and be done with it all. Also, i have shopped around for fat positive doctors and in my small town this is the best I could find. I feel stuck, like I need to get the surgery, because I can't even sleep without the pain.

Does anyone have any insight on this or any similar experiences? I hurt so bad it is hard to think about logically.