Welcome, and sorry you are here.
That is quite a blow for sure. Is it in any way possible this "baby" is yours? Is is also possible that she really is not pregnant?
Just having seen all the crazy stuff WS's do to "get out" or "get away" with what they have done, I wonder how true this is.
In addition know that this is not your fault. This isn't because you couldn't be ther perfect spouse, or because of your looks, or even because she couldn't have a baby with you. This is because she is broken, and needs to figure out why, and fix that.
Do see a lawyer/solicitor ASAP. Do Call your Dr and make an appt for STD testing, and talk about medication for helping you through this, even if it's just something that will help you sleep.
Take care of you. Be easy on yourself. Keep coming here, we will support you. If you have a good friend or close family member let them help you through this.
Your world has been rocked at it's core, and you are gonna need some support to find your feet again.