I've bumped my head several times since my initial injury without it making my condition any worse. While my recovery from the first injury has been extremely slow, I never flared up after hitting my head those few times.

Take it easy, accept things as they are, and take things as they come. You have a choice to accept your current situation or not to accept it. If you don't accept it, you'll feel miserable regardless of whether you have actually injured yourself.