Hitting a wall

If you have ever played racket ball you will understand my current mood. I feel like the ball, no matter how many times I am tossed against the wall I hit it and bounce back to continue to do it over and over again. I can bang my head a million times fight with myself over the same things and still end up with a headache at the end of the day. I will still struggle with injuries, food, mind set and all that and not get anywhere. I was so elated this morning when I weighed and was down 3 pounds. I even did a happy dance. Then I let my blood sugar levels dip to low I was way to hungry and went way to long with out eating I got shaky and felt out of control and inhaled all the food I could find to make me feel better while I was preparing myself a meal to eat. NOT once today but twice. Then I'm watching the biggest looser and feeling like crap wishing I could run just 1 mile not a Marathon but a single mile and then counting all my pain and getting more frustrated by the second. How can you exercise if your entire body hurts. I can not walk because of my heals, I can not bend to far or lift to much because of my back, I can not even type on the computer because of my wrists that and my knee and hit are burning. All this and I was told by the dr. I need to loose at least 30 more pounds by march to stay off of my heart meds. Where is my motivation? Where is my drive? I do not know. I need to get it back and get my body past this wall. I have never been a long jumper or a hurdler however It is about time that I get over it and just jump!