People touching my neck fear

I have a crazy fear where I'm afraid of anyone or anything touching my neck, is it normal? All the time I constantly think that someone is going to jump out and touch my neck causing me to always have a hand on my neck making me look like I want to choke myself :P I think it's because when I was a kid,my grandad would grab my neck harshly all the time till the point where I cried, don't ask me why....my dad's family is just weird. When ever anyone touches my neck I either quickly use my reflexes to slap them away, lash out at them, cry, hold my neck for the rest of the day or run away. I just can't stand it. Is it normal? Does anyone else have this fear?