Knee Reconstruction, Training Advice?

Unfortunately, just under a month ago I underwent knee reconstruction surgery(torn ACL and LCL) and I was wondering does anyone have any advice for training with this injury i.e Exercises/programmes for upper body mainly and please take into account I am restricted to crutches for the next 7 weeks.

I injured my knee playing semi-professional rugby and want to maintain my mass and also if it’s possible use this time to develop my upper body with a 5/6 day programme tailored to my needs. So if anyone has any programmes/advice please don’t hesitate in replying. Also if you have any nutritional advice please let me know as I am rapidly losing weight. I have lost over a stone since my injury.