Need help with a new exercise program?

I have arthritis in my back so that limits me to what I do. I was walking and that was working but got a wii game system at Christmas and an old problem that had not bothered me for years resurfaced. I have been to the dr over the last three months for planter flatitus( not sure about he spelling but is is like bone spurs that hurt very bad) and it is fa very bad case. Cortisone shots did not even help. I am only in my late 30's and I can tell everyday that it feels like I am having less and less energy I really need to so some kind of workout but it will have to be very very mild and then it probably wont help me. Anyone out there that can help I would love it!