So - what
exactly is is you are afraid of? If you can work that out, and then deal with that specific thing logically, it might help.
For instance, if you are worried about how the plane stays up in the air, then do a little bit of research into how it works, the science of it, what all the bits and pieces on the plane actually
do.
Have a look at this website
Coping With Flying Anxiety and Aerophobia at Fear Free Flying (UK)
which is full of really helpful information.
I had a friend who was terrified of flying. I sat with her on a flight and discovered that there were two things which worried her the most - the noise of the undercarriage coming up at the beginning of the flight, and going down again towards the end; and seeing the wing flaps moving when coming in to land. When I explained to her what the noises were, and why they did that with the flaps, she was much happier - in the past everyone had told her not to be silly, and had never explained what was going on.
An odd trick which works for me (I am not scared of flying, but I am terrified of the dentist!) is to think about your worry and your fear as a shape. Think about wrapping that shape up in a piece of cloth, and putting it into a box. Then imagine writing on the box "not to be opened until xxxx". Then every time you start to worry, remind yourself that you are not allowed into that box yet.
I
know that this sounds
very weird indeed, and you probably think I am nuts. But is has worked for me, and it will cost you nothing to try it.
When you go and see your doctor, I am sure that you will find that he has dealt with lots of people with fears like yours, and will be able to offer you some kind of help.
Good luck, and I hope that you enjoy your holiday.