Fear of helicopter flying?

My father is an experienced helicopter pilot with well over 10,000 hours flying helicopters and around the same amount for fixed wings. He is the operations manager for a helicopter company and I am always being offered to go on flights that would usually cost 350$ or more for free, with him or with him and other pilots in AS350 squirrels or R44 helicopters. There is just one problem. I have an irrational fear of flying, fueled largely by the fact that 2 years before I was born a pilot who was not stating his position, came round a mountain in his aeroplane and crashed into my dads helicopter. My dad managed to get it down but his foot is still painful for him today and the guy in the plane was killed. It's not so much an "Oh might god I'm going to die fear" its just that I can't relax in a helicopter, I always have to be scanning the sky for other aircraft and listening out for irregularities in the helicopters rotor sound. Another thing I don't like is sitting in the helicopter while the turbine spools up- cool sound but it makes my heart beat faster and faster until I'm a bundle of nerves. Today is my birthday and my dad was doing sound checks on the squirrel up over some of the most scenic coast in the country but I had to turn down his offer for me to come with him out of fear of flying. Now I'm sitting at home at the computer half wishing I was in the Squirrel, half being glad I'm on the ground. What places or sites can help me with my fear and get me flying ?