It is presented in rather an academic way, but if you click here, that will link you to a website which might help. It deals with many different irrational fears and suggests a variety of techniques for combating them.
Ask your GP to refer you to an Occupational Therapist. They can use a technique called Graded exposure or desensitisation to help you. Alternatively, a decent Hypnotherapist may help.
www.phobics-awareness.kickchat.com
this is a site for people with many phobias or anxietys, it has a chat room to chat to other suffers or a good forum with info etc...
I hear hypnotism is a good way and works for alot of people...
Hypnotism is kind of just a different state of mind... All kinds of fears / phobias can be overcome by this.
All the replys here are good advice,and try them out but also go out and buy paul mckennas change your life in seven days its not about claustrophobia its about the way we think about things if there negative thoughts he trains us to train our brain into making them positive i was a bit unsure at first but i swear its the best book out.i hope this answer is appropreate for this question its just i have many fears and the book is realy helping me.