Hi. Welcome. I am a Licensed Master Social Worker with more than 20 years experience working with individuals and families on a variety of issues.
The anxiety you feel before hand can be overwhelming for sure. Often worse than the actual flight.
Do you prctice any breathing exercises or self hypnosis?
There is a wonderful instant download that you can listen to every night that can come this fear of flying. You can find it here. http://www.stevegjones.com/fearofflyinghypnotherapycdmp3.htm
If this is not enough then I would strongly suggest you speak with your doctor to try and find out the underlying cause of this anxiety and fear of being closed in.
I see you are offline. When you are back on we can chat. In the meantime take a look and listen to a sample from the link above. It has been helpful for many people.