Injured . . now what!!

I am currently 6lbs away from my goal weight loss of 30lbs and 3 1/2 weeks away doing the Warrior Dash here in CT. I have worked soooo hard at both these goals. After recently getting divorced they were both soo important to me to finish and succeed. Now, I have a possible meniscus or mcl tear. . Im wearing a brace and couched!. NO work No workout. So now what do I do. . . How can still at least burned some calories laid up on the couch. How can I not loose all the muscle tone in my legs that I have work so hard at for that past 4 months. SOOO FRUSTRATED AND SAD!!! HELP PLEASE!!