Strength Training is the best for shaping up so if you aren't involved in that give it a try. Through a combination of strength training, aerobic training, and eating clean I've managed to lose and keep of 95 lbs. If I can do it, there is no reason that you can't!
I'm about 5 months post shoulder surgery. I get that recovery is tough and it takes a toll on your body. That doesn't give you permission to quit or stop trying to get better. You can do it!