I am just a strange bird

Hi .....thank you for this site. First of all, I'm a strange person in terms of "makes no sense" fears. I'm a photography studio manager from a very large company. I dearly love my work and position. However, it requires role playing at times and may require speaking to my peers at some point in time. I have had this fear my entire life, as long as I can possibly remember. I would "get sick" rather than give an oral book report in school. This sensation has remained with me all these years. However, there are times, I've made myself "do it" anyway. I fall apart..literally. I draw a "blank brain." These situations usually occur when I was not the one to initiate them. I must role play sales presentations with my peers at times. I would
automatically know all the answers if the situation happened with a real customer. I'm very, very good in real situations. I cannot deal with the unreal. I do, indeed, draw blanks....can't think...can't figure anything out. I perspire to the point of embarrassment. It's just awful. I must say though.....if I were the one to initiate the public "whatever", I'm usually fine. I'm the controller. Somebody else is not controlling me. "I" decide what I want to do and say. I'm not on the spot in front of people. I just don't understand how I can be one way and not be able to handle the other?
This fear overcomes me. I don't overcome it. I feel I can't fight it. It's so old...it's now part of me. Yet, I'm an excellent manager, sales person, photographer. I'm excellent in communication skills as long as I initiate. They have been my strengths on my bi annual reviews. Go figure. I can't put a finger on it. When I started with this company and had to go through extensive training with others in the same boat. I was so intimidated by them. I "almost" quit 50 different times, but I didn't. I started as a part time photographer and within 8 mo. was asked to take over one of the most difficult studios in our district. I've made constant improvements in staff, PR with our host store, sales, increased the client base....I won PR awards, customers service awards, sales volumn award. I was named manager of the district for the month of Nov. last year....the busiest month of the season in photography. All within one half year of becoming manager. I just don't understand my fear in these areas of apprehension with my peers. I'm sorry this got so long. I'm a strange bird. Trust me. Anyway.....thanks for your time.