anxiety
"I have had anxiety/panic disorder for 8 yrs now. When I had my 1st attack I went to the ER and they just told me it was all in my head, wrong. After about the 7th one is when they  said I have the disorder, they tried everything you can think of until my Dr. tried clonazepam every since then I take as directed and I'm doing wonderful, I've had a couple of small ones since but nothing compared to before. Just remember, you are not the only one with this problem, I thought that for awhile myself until I started talking to other people with the same issues. Hope it helps."