The same exact thing has happened to me twice in the last few months. First I thought it was a reaction to some pain meds the dentist gave me, and did not think anything of it. Then it happened again like two months later. I feel totally fine when I go to bed, then when I start to dose off it feels like I am paralyzed and my heart is literally vibrating. Scarry as hell! I have also been off cycle for like 6-7 months.