You can easily add more protein into your regimen by starting with your daily water-based moisturizers first. There are many that are protein based, and these are great for giving you a small daily protein boost. When I feel like a need just a bit of protein I'll use something like Cantu Shea Butter Break Cure or Profectiv Break Free. Thats one way to get more protein without washing your hair.
Now, If you feel like you need more lasting protein, you can simply do a mild protein deep conditioning with something like Aphogee 2 minute keratin reconstructor, Mane N Tail, ORS Mayo, or LeKair cholesterol. Just alternate your moisturizing deep conditioner with a protein based conditioner, and that should help you out some.
HTH.