So.....
1. Your ex needs a post nup - giving her everything, in order for her to "feel safe" about going on with the marriage.
2. You know about said post nup for weeks; discuss it with her from time to time since you're uncomfortable about parts of it.
3. She tells you to sign it and she'll fix it later to be more even. Says you can trust her. The person who doesn't like you any more and wants out. But you can trust her to look out for your best interests.
4. You sign it after lots of weeks and at least a few discussions with her without any of the changes you desired.
5. After you sign it, she files for divorce and wants to enforce the signed division of property document as is.

I'm very sorry for the pain and rotten situation you're in. Unfortunately, and I could be wrong, but it appears to me you did everything wrong in dealing with this situation. Forget the marriage part, I'm just talking about the post nup. You knew about it for weeks before you signed. You discussed it with the other party several times. It was never changed. You signed anyway. These actions don't appear to be a great defense for your cause.

Tough lesson hopefully learned - you don't sign one-sided documents hoping to get a better deal in the future from the other side.

Again, sorry for you in your situation; I say cut your losses and run.