Paxboy
What experience of desensitisation of fear do you have?
I made my suggestion based on real experience. I also have psychology qualifications and 15 years experience in working in the area of behavioural change.
Remember that a person on a trial flight (which last about 20 minutes) can be on the ground in under 5 if they feel uncomfortable.
Desensitisation is achieved by confronting the fear in a small way and then increasing the intensity of the experience.
Given that the OP is an adult, a trial flight is one of a raft of possible options.
Whilst the OP will know whether or not this is an acceptable starting point (it may not be), I don't really think that you should dismiss the idea out of hand.