yep.....more than a few times......one time i pulled over on the interstate and had to lay on my truck seat and cry for 20 minutes....

i take Klonopin now, so my attacks are few and far between

you did the right thing by pulling over....I try to close my eyes and
take really deep breaths and focus on something in your mind...a special person, special place, anything to take your mind off the
unknown

hope this helps