Higher protein diets do nothing but give more calories and throw off your metabolic processes.
Your body can only metabolize so much protein in a given day via the liver and the kidneys. Forcing more protein through is taxing on the liver and when the kidneys recieve the excess nitrogen-ammonia-urea it considers this toxic.
In order to maintain weight loss do not push your protein too high, as there is no benefit. rather, keep your protein adequate (notice the word choice) and focus on your carbohydrate and fat intakes. lower your animal derived fat sources first (dairy and meat) including whey protein (which by the way doesn't work, your body adequately recieves the needed 1.5g from milk sources daily--if you consume fat-free dairy. so not supplementation is necessary)
then focus on your cooking oil choices, and go for the monounsaturated olive oil but be careful b/c 96% of the caloric value from olives is fat--a little goes a long way.