I'm in a similar state to you. I do basic and light physical therapy. I go for long walks, I try to stand as much as possible. And I highly recommend you practice good posture 24/7. Honestly we are in the same boat (I might be worse off.)
I would say stay away from the weights. Just do basic body strength exercises, light but frequent, to build up a foundation so that you dont wreck your joints. Pay attention to inflammatory foods, and try to aim for a anti-inflammatory diet.
Finally, if you have a hard time eating protein, go by some whey protein! Guzzle it!