I had no idea that other people felt the same, or worse, than I do! I used to fly with no problems whatsoever, but then for some reason started getting airsick. That led to anxiety about it, which led to general anxiety about being on the plane, which led to a kind of claustrophobia as well (a feeling that I have to be able to get up and move, and a fear that I'll freak out if I can't). I've never had to leave the plane - my problem mostly kicks in an hour or two into the flight (and I live down at the bottom of Africa, so it's always an 11 hour flight or more - and being in a state for that long is not fun). And because of the airsickness, I can't distract myself easily by watching a movie or reading, because that aggravates the nausea
I find it's slightly better to sit near the front of the plane (well, front of economy - business is incredibly expensive here). Not right up against the bulkhead, but a few rows back. Seeing rows and rows of people in front of me seems to make it feel more crowded and close.
But my doctor's given me new tranquilisers which seemed to help a bit the last time, and a friend passed on a new anti-nausea tablet which seemed to help as well, so there's hope. And as hard as it's been to read this thread - just reading about it causes that feeling of claustrophobia to creep up on me - it's given me hope, too, that if I do freak out it's not the end of the world; the flight attendants will cope; and the feeling will pass eventually. So thanks for sharing your stories.