Yes, it's fine to add peanutt butter to your oatmeal. Anyway your diet kind of sucks. Why some many protien shakes? You need to eat real food. Shakes and mrp's are a money making fad for the most part by suppliment companies. The advantage to the shakes is the fast absorbtion of whey protien, thus making it useful as a post-workout recovery meal. As far as eating it 3 times a day like you're doing? Its silly. Plus you are only eatng 5 meals a day counting the shakes. You need to be eating slower absorbing foods, with a higher meal frequincy. Eat more real food, and get a minimum of 6 meals a day. 8 or 9 would be better if time constrants allow for it.