jrmbothell

Thanks to the folks who are posting here with their experiences and suggestions. Most of the trouble spots and triggers mentioned above apply to me. I've had claustrophobia on and off for years but this last year or two on planes has become really tough.
Aisle seats near the front, check.
Some control over ventilation, check. I use a battery-operated, fairly powerful hand-held fan but sure appreciate overhead air too.
Avoiding stimulants ahead of time, check.
Breathing exercises and meditative music or other recorded material, check.
Cold bottle of water before boarding every flight, check.
Avoiding small planes like bombardiers, etc., check.
Notifying flight attendants ahead of time, I haven't been doing that, but I sure like the idea, glad to know from some other forums that the FA community is open to that. I have certainly had to engage them more than once by walking up to the galley when I was having trouble. Very grateful for their help.

So, on medications...
Caveat here is that I am a physician.
The benzodiazepine medications are extremely helpful when used for situational anxiety, at the right time, and at the right dose. My main thing is to really encourage people to have a conversation with their PCP about this, or psychiatrist if needed. For people who are on a lot of complicated meds including chronic pain meds, etc. the advice can be very different and honestly the benefit may not be as solid.
Personally I use Xanax from my PCP, taking it at least 30 minutes before the flight, despite the "rapid-onset" action of this drug. For each benzo, duration of action is longer but also the onset will be slower. The order goes Xanax (alprazolam), Ativan (lorazepam), Valium (diazepam), then Klonopin (clonazepam). For my flights mostly on the West Coast, Xanax is OK, though it does sometimes wear off before landing which sucks.
But my other important bit of advice here is to also ask your doctor about using propranolol (Inderal). It's the old "beta blocker" which has long been the most commonly used medication for stage fright, speakers anxiety, etc. It is not a sedative in the same sense as the benzodiazepines, it's simply blocks the adrenaline rush that contributes so much to the panic experience. It is used chronically as a blood pressure medicine but those who need it for this purpose are probably taking a longer acting medication instead like atenolol or metoprolol. Old-fashioned short acting propranolol is cheap and can be used in a variety of doses, obviously starting low (10 mg) first. People already on blood pressure meds or who tend to run really low BPs will need to be very cautious about low blood pressure with standing, dizziness, even fainting, so this is definitely one to talk with your doc about. All these problems can be worsened with alcohol, caution is certainly advised. Some people just use propranolol for situational anxiety, though, and they don't have to use the real sedatives (or alcohol), so they are more alert on arrival at their destination.
Hope this helps.
A big thanks to all the flight attendants out there who help us.