Ok, so I am hardly an expert since I'm only 7 days post-op myself, but I think you might need to cut yourself some slack. Even though you don't have outward signs of major surgery, you did, in fact, have major abdominal surgery. It will take time for you to get your energy back. Low energy levels are your body's way of saying "I'm still healing...all energy should be expended to that result".
As for the Protein shakes, etc., I'm with you on that....I don't like them. Didn't like them pre-op, and like them less now!! My philosophy is that I will follow the rules as closely as I can, and live with it. Eventually it will all settle into normalcy.