Seizure? Or POTS symptoms? Help!

[NicoleAdia]

At least once or twice a month I wake up in the middle of the night with an episode that goes like this:  Within two minutes of waking up, nausea sky rockets and I feel as though if I move, I will throw up.  Then (usually starting in my legs) my body begins shaking violently.  Sometimes I get extremely hot during this and have various other symptoms but the shaking and extreme nausea are the worst.  The other night, it was the worst it's ever been and my husband is convinced it's a seizure.  My body shakes so violently that my muscles get tired and my teeth are chattering so hard.  Any ideas or experience as to whether it's merely adrenaline from POTS or if it may be something more?  Thank you!!