Mind vs. Body

My mind and body are in a major battle right now and I honestly have no clue which one will win??

My mind wants to work out and run more mileage.
My body doesn't agree. My knee is messed up again and doesn't want me to work out or run more.

My mind wants me to eat junk food.
My body says "Look at me, you don't want that...."

My mind says get off the computer and do something productive
My body refuses

My mind says get to bed early and get more rest
My body refuses

Do you see the pattern here? For the most part (minus the junk food), my mind should be winning, but for some reason the body is and that is frustrating. I posted that horrendous picture of me and was so motivated for a bit and was doing wonderfully and so proud of myself. Then, I have no clue what happened. I still am exercising well and would be more if it wasn't for the stupid knee issue, but my eating and lounging is out of control. I am working on the knee, but I need to get past all the other issues. Someone kick me in my arse.....PLEASE....tell me to be smarter. I know all this stuff but like I just said earlier--I simply don't practice what I preach.