A: One of the things I would consider is calculating your daily protein needs to see what they might be and going off of that. I would look into doing a gut test, like a GI-MAP, just to make sure you don't have anything that's causing histamine issues in your body, such as H. pylori or Blastocystis hominis, before you assume that you have a genetic histamine intolerance. Unless you've been specifically told that it is something genetic.
As far as proteins, eggs might be an option that people find easier to digest. Also, some proteins like fish might be another option for you to incorporate.