I have recently injuried a ligament in my chest which pretty much halts any kind of exercise. I am confussed on how should I eat while I take sometime off. I was curretly on a mass gain diet high protein, fats, moderate carbs.

Dave,

You may want to drop the calories back a little because you are not going to be burning any off in the gym. (if you are concerned about fat loss). Make sure to continue your supplement regimen so you have a faster recovery and less muscle loss.