Hi,
I've had what you're talking about for a day, maybe two. It's happened a couple times, but I've always been able to point to the event that caused it, and it has always subsided with time. I can't give you much advice, but I can try, and I can offer thanks for sharing this profound moment with us.
1 - Fear Not! Whatever part of you is running this (or visting angel, or whatever else), surely has your good in mind. Trust the experience, and allow it to change you.
2 - The fastest way to make this feeling disappear is to try to understand it. Your call whether or not to try. There's a chance you'll succeed, and that would be well worth it.
3 - Are you sure you didn't have a shock to your physical system? That wouldn't invalidate the experience, but it would be healthy to know any material causes.
And please, when you can, share more.
Yotam