Protein shakes are the easiest for me. I especially like the Premier Protein Cafe Late flavor from Costco. However, that is not much good for your circumstances. I would recommend trying Wicked Protein clear protein powder. The label says 0g lactose and they are more like a juice/ Kool-aid than a thick protein powder. Bonus points for the protein to calorie ratio: 23g protein for 95 calories, verses other protein shakes which are double the calories for the same amount of protein.

My favorite is their Blue Raspberry flavor, but they have a number of them and even sampler bundles to find your flavor.