Boy, you have received a boat load of good advise. Some of it will be helpful. Some of it won't. If there was a silver bullet, we wouldn't be here I would just add that you need to be careful about the type of exercise that you do. Until you get this nailed down, I would confine it to power walking and resistance bands. You don't need to be jarring things. Back when I was able to, I did 30-45 minutes at 4mph and that was intense enough to raise the heart rate and work up a good sweat. I did this in the early morning and often repeated it in the early-mid afternoon. This got those endorphins pumping, improved my mood, energized me and actually reduced the pain levels somewhat. The resistance bands help with upper body strength but can be used elsewhere of course. Hang in there.