I am 42 year old. Till now I am very afraid of people when they speak loudly to me or scold me. My mind goes blank with fear and just obeyed what others wants, irrespective whether his request/order/scolding is acceptable to me (or not). When someone loudly and aggressively talk to me, I goes into fear state and doesn't courage to neglect or deny him. This thing mostly happens when I interact with strangers/new people/ people in authority.
For example : I participated in a community service in my local area. One man certainly came and aggressively and loudly demanded to take photograph of me and my wife. I was frozen with fear what to do and he wanted to take photograph of himself with my wife and he did.
In another case, in barber shop, I went with my kid to cut his hair. I was saying to barber how his hair should be cut (in what shape & style), but barber interrupted me and said firmly ' go to there and sit there' and I become frozen with unknown fear and just followed his instruction. I just accepted the way he want to cut, not the way I want.

Till now I am living my life with with fear. I want any suggestion on cure.

thanks