What's more important than protein in your case (because it sounds like you're not a vegan and probably consume all sources of protein easily) is consuming enough calories. There's only so much your body can do with the protein you eat if you don't give it enough total energy (food calories) to assemble the amino acids into intact protein. Making new protein is endergonic- meaning energy needs to go INTO the process to make it happen. Unless you're overweight and have a bank account of energy as body fat to use to make skeletal muscle protein, you need to eat a surplus of food calories.
Eat frequently. Lift weights. Make sure high-quality protein (dairy, beef, poultry, fish, soy, pea) is in every meal, especially postexercise.