Hey man, I was in your shoes 2 years ago. I went from 280-250 in 2 weeks and I was winded very easily probably because I was stoned all the time from all that anesthetic they used on me. The doctors told me I couldn't lift anything for at least 6 weeks, but being a meathead I started lifting 2 weeks later. I found running to purge my body of the drugs they put me on helped a lot I also did pushups (trying to get to 100 consecutively) and shoulder exercises with bands daily I did bodyweight squats as well. When I was in the gym, I really paid attention to my body trying not to make any sudden movements that could end up turning into a hernia. I suggest you do the same, I lifted moderately heavy but limited heavy sets to 1 or 2 for about a week or 2. I also did a lot of high rep squatting and until I wasn't gassing much anymore. Be very cautious when you do pulling movements like pullups or rows, I didn't really have a problem with deadlifting though. Just watch yourself for a few weeks and slowly progress as your pain goes away. Eventually start working your core to strengthen the muscles on top of squatting and deadlifting and stuff, but keep heavy core work light until you are pain free. As far as nutrition, you can still be fine without supplements. I used a massgainer cause I had to gain my weight back for football. my strength came back pretty quickly making jumps in bench, squat/dead every week after that. One thing to watch if you choose to go the mass gainer way is that you will end up with some good fat with it. I had appendicitis in May, but by the end of the summer I was back up to 275 and my lifts were back up to what they were before. I focused size more than strength. Another thing to note on is that you are on the right track with the stretching. I didn't stretch my hips much during my recovery and I became tighter on the right side. Good luck with it man, and listen to your body. (so cliche, but true lol).