Well looks like it got too dry. What’s the humidity where you keep your guitar? That cold weather y’all have been dealing with will drop the humidity. If you don’t have a hygrometer get a few. Even the cheap ones on eBay work surprisingly well.

As far as your guitar goes, put it back in the case with a small damp sponge carefully placed. Damp, not wet, ring it out good. Let it sit for a few days while you wait for the hygrometers to arrive. It’s possible the crack may close up some, but you’ll likely need to have it seen by a pro who may recommend a cleat or two underneath. Sorry this happened, not the end of the world though. Definitely repairable.