My first bout of claustrophobia hit me at a wet t-shirt contest in Matamoros, Spring Break '93 when I was 21. Was enjoying the show and one nicely proportioned young lady removed her shirt and the resulting crowd press toward the stage triggered my lizard brain, and I noped the fuck out, losing my glasses along the way. I was terribly nearsighted at the time, but I did not care at all.
Didn't have another incident until I went through Navy firefighting training in summer of 1995. Got into a room with about 20 other students in full firefighting gear with an oxygen breathing apparatus to fight a "fire" in a mock engine room with natural gas flames. The air got squeezed out of my OBA bladder which slowed the chain reaction in the OBA and kept me from being able to get a full breath. Again, I noped the fuck out of there. If I had failed to complete that training, I would have been processed out of the Navy. I spent the next two weeks wearing an OBA for two hours a day at a desk while studying prior to taking another try at the firefighting training course. Barely made it through the course on my second try and was fighting panic the entire time.
I spent decades avoiding situations and white-knuckling it through those I could not avoid. Finally said to myself, "this is dumb" and swallowed my pride and went to therapy.
Now, I'm not about to go spelunking where I have to squeeze through crevices, but reading about it no longer gives me sweats. And I don't stress ahead of airplane flights anymore.
If this is something you struggle with, it can get better.