I had a tooth break while eating a raw green bean I plucked from the garden while pushing the lawn mower. I was horrified. Running your tongue over it probably gives the sensation of being worse than it is.
I believe that like the rest of the body, you are somewhat predisposed with the cards dealt to you, including tooth strength. Sure, you can hedge your bets with good dental hygiene, but sometimes even the best care won't overcome your fate.
The good news is that today's dentists can repair nearly anything. There's a good chance you may have to get a crown. It's not the end of the world. But, I can empathize with that gut wrenching feeling when it breaks and you suddenly feel like all heck has fallen on you.
Rest assured that it can be fixed. Call your dentist in the morning. Often, they will squeeze you in for a quick peek, do whatever might be necessary to protect you, and set up an appointment to take care of it.
Take a deep breath and realize that it can and will be fixed.
Take care.