New anxiety about flying, where's this come from?

I've had health anxiety for ages, of varying severity, often caused by triggers I know about but quite often it happens at random.

During all this time, I've never been on a flight just because I hadn't needed to.

Two days ago, I booked a quick flight from my home town to someone just an hour away. Pretty much ever since, I've had fast heart rate, over 100, pretty much constantly and an achey tight left arm. In my head, I'm not thinking about the flight, but the timing seems coincidental.

Right this second, I'm sat in departures, waiting until 2.35, and my pains are pretty bad, feeling of wanting to escape is strong and I feel like bursting. It feels like a heart problem obviously!

I've no idea where this fear has come from. I used to fly quite easily. It's only a short flight. I'm not consciously thinking of it, or imagining crashing etc. I think I'm afraid of feeling ill on the plane because there's no escape.

Has anyone else suddenly developed fears of things they used to do, and has anyone got any immediate calming techniques?

I develop new anxiety triggers all the time
Yours could be a sub-conscious thought of all the messed up stuff going on in the world right now. Have a few drinks before you get on. Might ease the tension

---------- Post added at 00:52 ---------- Previous post was at 00:46 ----------

Try walking around the airport, buying a book or magazine you find interesting, make sure you have a little bit of food in your stomach. Being anxious on an empty stomach can cause an even faster heart beat and nauseous feeling