I don't eat fish, so can't comment on that. I do eat a lot of chicken, I buy the Perdue Perfect Portion tenderloins at my local wholesale club for grilling. For chicken dishes, anytime chicken breast is on sale, I stock up and freeze it in 1 lb portions. I consider $1.99/lb a stock up price. Turkey tips are awesome too. For flavoring the chicken, watch the marinades. A lot of the commercial ones contain a lot of sugar. Dry rubs are best, but I still use a marinade here and there. I have a couple of chicken/pork recipes you might like.
Breakfast? You are not limited, at all. Fruit is always awesome. Oatmeal. I love oatmeal and eat it almost every morning. I keep packs of Better Oats at my desk at work, for when I forget to bring homemade in. I make my own oatmeal from steel cut oats and add my own ingredients. Yogurt I love. Stay away from the ones that are flavored, they are full of sugar, usually between 20 and 30 grams of added sugar. I buy Fage 2% plain Greek yogurt 7 oz and add a couple tablespoons sugar free jam and some fruit. Today for lunch, I had that with sugar free apricot jam and I cut up some dried apricots and mixed it all up. I added some chia seeds, 21 grams of protein right there. The other day, I used raspberry sugar free jam and added fresh raspberries to it.
Fresh spinach is cheap, saute it with a little olive oil and garlic. When done, dress with a little grated romano or parm cheese.