I hear you on the headache front! I get full blown migraines with artificial sweeteners of any kind and I don't get migraines ordinarily.
I swore of "diet" foods (non-sweeteners variety) because they made me constipated and lethargic. Best switch I ever made! But convenience foods (lean cuisines, protein bars, Slim Fast) got me through the first few months because they were easy to count.
Learn to cook one new thing a week, or even once a month. Your skills will deepen.
Chicken is pretty easy to start with. Stir fries are easy and hard to mess up. Just put a Tbsp of oil in a Wok or skillet, cook small pieces of chicken about three minutes after there is no longer any pink, then toss in favorite veggies, fresh or frozen. Sometimes I throw in spices (garlic, cayenne pepper, chili pepper, ginger) and sometimes I just leave it as is. Serve with brown rice.
Another easy chicken dish is to throw some BBQ sauce over chicken breasts and bake at 350 for 30 minutes. I like to butterfly my chicken because 1/2 a breast is a serving, but you don't have to do that.