Pretty sure it was a seizure. Or stroke....😱

My fiancé and I have been together for two years and have a 5mo son. I have three older daughters from before. I’ve never had an orgasm from sex until him. At first I’d hyperventilate and cry. A lot. But last night I’m pretty sure I would’ve benefited from an anti seizure med. I literally convulsed. And then I cried because he didn’t finish. Because I screamed so loud I woke up our middle daughter and couldn’t breathe so he tried to help by rubbing my back and playing with my hair. I guess about 10-15later I finally passed out still convulsing. He said it was a full body and/or aftershocks...? All I could focus on was possibly being inadequate. I’m frikin 32 and cant handle an O?!

Is this a common occurrence? What can I do to handle it better? THANKS y’all!