Welcome to the forums.
I fully understand the weight gain issue. I think mine is more onthe lines of "well, if I feel like crap, I'm going to eat like crap". I too had lost a lot of weight, and gained a lot of it back. It's very hard for me to exercise, or even eat right for that matter. It's great that you're back on a health diet and exercise. How hard is the exercise for you?
Also, what style of Karate do you study? I too use to study martial arts before this happened to me.
Suffering from Adrenal Fatigue (confirmed by Saliva test)
6000mg of Vitamin C daily
800mg of Vitamin E
1000mg of Vitamin B5
100mg of vitamin B6