I understand your dilemma as I recently went through the very same incidence at the airport. My "Deaf On Left" pin, purchased through the ANA stops any and all misunderstandings, but one has to put this into the "bin" before walking through the metal detector. My husband assists in moments such as these. And if he's not there to rescue me, I just tell myself "What the hey? Not much I can do about this."
Please don't think about tasers, etc. as this only fuels unwanted fears. Doubts this will happen anyway. I remember fueling my own fears about being pulled over and given test for drinking and driving, but knowing there isn't much I can do to avoid a situation such as this, only endure the humiliation realising the tables will turn once the officer understands. So, try to relax and find the humor, it's there, trust me.