You have strained a muscle that is pulling on your vertebrae.
You need a chiropractic adjustment, but if you can't or won't do that, magnesium glycinate or a soak in a very warm epsom salt bath, a massage (Yo! Fiance,.....), gentle stretches, lie back on a pillow that supports your neck's natural curvature or all of the above. It should then click on it's own and you'll feel good as new.
Sometimes, just a good nights sleep will put it back right.
Chiropractic would push/pull/put your vertebral alignment back into place and then the muscle would relax or the other stuff will loosen the muscle enough to let the vertebrae slip back into place.
Thanks for coming in. I'll send you a bill.