I had knee surgery and was given therapy exercises by physical therapists. Obviously the exercise changed as time went on. I couldn't believe what a workout they were.
I broke my femur and have a rod and screws in it now so I know your frustration. I am now back to jogging but what I found was starting with walking. The exercise bike was also an option for me. Also there are plenty of upper body exercises. Stick with it as much as possible because if I go we week without exercising (even just walking around the block) then my leg and hip ache so much. you just have to build it up again. Im two years on and still in pain but each day it gets stronger. You can do it!!!! :-)
Do your physical therapy as soon as they send you for it. my boyfriend had knee surgery. Obviously you need fewer calories while you are sitting around, elevating your leg to let it heal. Try not to sit around eating. With my boyfriend I made him sit out on the front porch because the weather was lovely so at least he got out of the house and off the couch. He sat in a chair with his leg elevated there for a change of scenery. Then he did physical therapy. He thought the exercises didn't look impressive, But he did them and it helped him so much, and he had the best looking legs he's ever had.