I fly United almost 200K a year. The last thing in the world that
I was, was claustrophobic until a year or so ago. The last few
years I have had to fly hundreds of flights on United small planes
and it got to the point that if I did not have a isle seat near the
front of the plane I would start to almost freak out, as a 1K MM
I usually got the seat area I wanted but a few times with weather
etc. I found my self in window seats totally in the back and
actually got off the plane and waited several hours for a bigger
plane.

Finally I talked to several doctors who specialize in claustrophobic
people and all of them said this was becoming more and more
common with people who fly a lot.

One doc gave me a RX for alprazolam 0.05MG and told me to take
one before flying on a small plane, I have not tried this yet as I
refuse to get on one.

Believe me it can happen to you, its not fun.