Tina,
In the days after my exploratory laparoscopy (back sometime in the mid-90's), I would nap in the afternoon, and wake up in a terrible fright! Like fighting to wake up, totally panicked. This was in "pre-peri" days. I assumed it was related to the surgery, which was relatively minor (even tho' I was one of the lucky ones who took a full 6 weeks to recover)

.
My friend's 2-year-old daughter had to undergo heart surgery a few years ago, and for months afterward, would wake in a complete panic. Her parents had to sit with her for almost an hour for her to stop being upset.
I honestly think these procedures, even if not hugely invasive, are still a shock to our bodies, and the repercussion can manifest in panic attacks. AND remember the huge blood loss you had...
Take heart, Tina - you just had this done, and it may take a little while to recover. Don't fear the panic attacks; tell yourself again and again, "These are only physical sensations. I can just go about my business while feeling this way."
Let us know how you are, dear Friend. We care about you.
Luv
JJ