I think Jaybee is very correct on getting rid of the junk food. Since I took a pledge to cut out junk food in my diet I have done pretty good. With start of my exercising again I feel real good and I am getting myself back into a better shape and outlook.
I think that with all your doing you may just be over taxing yourself. Making sure you well hydrated is a good start too. I cut out all caffeine from my diet three years ago I think and I feel great as I drink a lot of water daily. I am drinking 3-4 liters a day and while I may spend more time in a bathroom I still feel great. I know watching what you eat is a big step and I am still approaching that hurdle in my life. Good luck with everything in yours.