Halcion (triazolam) and Valium (diazepam) are both in the same category of medications ("benzodiazepines"). So although the former is more commonly used for sleep, and the latter for anxiety, they might work well for either purpose for a given individual.

It sounds like both of you have good techniques for dealing with both claustrophobia and fear of flying.

For a plane that is too hot, especially sitting on the tarmac in the summer, I think an old-fashioned fan works well. I have one that folds up to a size only a little thicker and longer than a pen, but opens into a very functional fan. Also, the battery-powered mister fans are helpful. Turn the switch to "On" and point the fan at your face/neck, then squeeze the handle to get a mist spray too. Take it through the checkpoint empty, then fill the water bottle part on the other side. I got mine at a theme park on vacation, but they are frequently available in the "seasonal items" aisle of your local drug or department store.

I don't have a specific problem with claustrophobia, but the wide body jets just seem more spacious to me, the narrow body aircraft less so. And maybe it's just me, but I don't recall needing the personal vent on a wide body (or whether it's there or not) but I use it all the time on domestic narrow body aircraft.