Returning to work in 2 weeks and I'm so scared.

I have to go back to work for financial reasons, and my 12 weeks are up in 2 weeks. My baby will be 10 and a half weeks old when I go back. That's its own issue, since I don't feel he's old enough to be away from me and I'm not emotionally ready to be away from him for more than a few hours at a time.

But my biggest concern is that I work with troubled teens. It's a fairly active job, with lots of walking and stairs on a normal day, and intense physical restraints of violent/unsafe students on a bad day.

I had a C-section that I recovered from fairly well, but at 8 weeks postpartum I still tire very easily and feel stretching uncomfortable sensations in my lower abs and hips if I do too much. I'm very nervous that I won't be able to physically handle my job at just 10 weeks after having a major muscle group cut in half.

Any advice?

Look at him! How do I leave him?