Last Night At A Restaurant, Waiting On My Food, I

Last night at a restaurant, waiting on my food, I started sweating profusely, my neck got stiff, and I felt nauseous and a little faint. I take meds for high BP and a couple times I have felt sweaty/clammy and stiff neck, I checked and my BP was way too low. But I never sweated so profusely and I never had nausea from low BP before. Was this something different?