Sorry to hear about your injury. It does take time to even realize this is not a dream. I found laying on my back so hard. My butt felt like it would fall off. Do eat healthy, you will find that you do loose weight. I believe this sight says it takes 3000 calories a day to heal a broken bone. These are the leg exercises I understand a person can do. 1) ankle bends, and circles with ankle 2) stretching toes 3) straight leg lifts. 4) carefully bringing foot up and bending the knee.
It has been about five months since I fell and I am much better. Not like I think I should be, but I can walk about a mile. Still limp when I get tired and my foot bothers me more than the leg.
Hang in there and be sure to go to physio once you are weight bearing. They seem more helpful with recovery than the surgeon.