Welcome to the world of being a senior with perceivable disabilities. One of the suggestions was to organize a class which is an excellent idea.
I am a NRA Instructor, 65 years old, and suffer from a severe spinal cord injury. It might be worth contacting the NRA to see if they can provide you with a list of senior (older) Instructors that can appreciate your disabilities. I think they will have more patience and understanding and could better relate to you. Not to say the younger guys couldn't... just a thought.
Like you, when I was a lot younger, I would kick butt and take names. If only I could do that today..... And, as you observed, you take the hand that is dealt to you as it sure beats the alternative.
May the Schwartz Be With You.
NRA Life Member