High protein is what you would want, but I'm skeptical of low-carb diets. You also shouldn't overdo the high protein part of it all. As a rule of thumb I'd say stay below a gram of protein per pound of body weight, or below 200 grams of protein if you are really big.

Whats typical for people who want to build muscle is that they use high protein together with high carbs (carbloading) and relatively low fats. As to carbs and fats, you are doing the exact opposite.

Unless your protein is dangerously high, I'd say the best you can do at the moment is to add carbs, but this in the form of vegetables and fruits. If your protein leans heavily on meat, drop some meat and add more fish.

Toss a pound of vegetables and two glasses of fruit juice (not the sugared stuff, pure juices) in there and see what it does.