eating healthy is incredibly important.

if you're not already on a multi-vitamin, get one! b12 is good, but it's not going to do everything for you. I think it's one of the most important things you can do when you're aiming to get healthy. I really like liquid multi-vitamin complexes, the one I take is packed with good stuff (it's far more than just a multi-vitamin):

http://www.vitacost.com/TRC-Nutritio...lete-Nutrition

whenever I am feeling sluggish during a workout, I mix cayenne pepper, lemon juice, honey, and apple cider vinegar in water. it's better (for me) than any energy drink!

I think as you heal your body, eating healthy foods, and replenishing your body of minerals and vitamins... you will naturally have a boost of energy and endurance, and the weight will melt off.