Tapping is about surviving the class, and making it back in a day or two to do it all again.
People who don't tap aren't cut out for the sport, they'll be sidelined by injury or quit due to frustration.
As far as tapping from a panic attack, you probably went beyond exhaustion and freaked yourself out, I would work my way up to more than one class in a day. Trust me, the school will still be there in 4 months, don't burn out.
I've tapped from exhaustion plenty of times, I've also tapped from the following:
- Knee on belly
- Cross collar choke that was pressing on my face instead of neck.
- A headlock that wasn't on my neck
- A purple belt using his fist to get to my collar while I was guarding it with my chin.
These are all weak reasons to tap, but at the end of the day, I keep making it back to class, and I don't tap to these kinds of things as much today as I did two months ago. Keep at it, keep getting stronger, and for god's sake, tap early - tap often.