Had back surgery and now I'm ready to get back in shape! I need motivation!

I had back surgery 3 years ago from a softball accident. I used to play sports all my life until age 27. I need to get back in shape as I have gained about 40+ lbs since surgery. Meaning it is even more dangerous now to carry this extra weight! I need help with motivation and encouragement. I want to do this but I am so scared that I will pull the disc again and re-injure it to where I can't do anything but crawl again. Any suggestions and tips on how to get my arms and back --back into shape would be awesome! I have recently noticed back fat and lower arm fat due to muscles turning into fat. I need good exercises to help tone those areas up again. Naturally, lower stomach fat has developed as well and that is a huge concern for me too. Any suggestions that WON'T ruin my L5 and S1 again would be EXTREMELY helpful. I'm scared sit-ups will pull it again and lifting will pull it out again. I spent 9 months in agonizing pain where I almost literally crawled into the hospital for surgery because I waited too long to get help---only making the surgery that much more invasive.
SUGGESTIONS? Or anyone want to add me as a friend and lets get connected and push one another. I'm new to this fitbit/vivosmart device and app, so I need people to reach out.

THANKS!!!