what is this?

i have only had two serious panic attacks in my life and neither one of them were caused by any sort of traumatic experience. in fact they both happened on relatively normal days.
if you have ever had a panic attack let me tell you they are scary
you feel like your heart is going to jump out of your chest
and you can't breathe
and all sorts of weird thoughts go through your head
and with one i actually vomited

so lately i have been having these little panic episodes
 disturbing
these creep up on me first with fluttery heart beats
then the swirly thoughts come in
and i feel like i am detached from where i am
and finally i begin to self doubt
HUGE
like- why am i teaching?  my art work is all crap.
who am i kidding? i don't know anything.....
and it goes on

and then all i want to do i crawl into a ball and do nothing
cuz if i do nothing then no one will be able to see that i
am an impostor.

where does this come from? everything was going so well
then
CRASH!