Hi momoftwins and welcome to HW.
They tell us that panic attacks only last for a short "discrete" period of time, but I for one disagree. I have had attacks that lasted well over an hour. You are not alone in this. Having just got through my own finals I can empathise with things being anxiety ridden at this time. Often, after an anxious time we can have a panic attack seemingly "out of the blue". It is scary and unfair, but as we relax, our mind can take over and let out the anxiety we suppressed.
Boooo!
I would reccomend seeing your normal GP (doc) and asking for a referral to a counsellor and maybe some stabilising medication until things get a little better for you. I wish you all the best. This is tough stuff, but know that at HW we will be here to listen and support.