it deff could be look i was very dis couraged when i had my last panic attac as well but youve got to realize that ther allways going to came and go no matter how much you hate them once they start you caint stop thenm and when they wanna come there going to come just keep your head up just do the best you can do to controll it other then that theres nothing you can do.
But remind yourself that your not alone=]
First of all, measure your progress by all the days you've gone without a panic attack, not by the one that hits in the middle of your progress! It may have been that the noise startled you and set off a panic attack, or it may have been coincidental. But you are doing sooo good, and you will have setbacks from time to time, but you are still making great progress!!!! Don't get discouraged, this all takes time. You're being too hard on yourself, and this you don't need. Stay positive and continue to move forward. Don't get down on yourself, instead just think "hey, it's been a long time since this happened, I've really made progress here! Count the good days, not the bad. Take care!