Not an expert by any means on this, but a friend of mine at work went through the same thing a few years back. They were married for 20+ years and their kid was all grown up (20's), so no child support. Got screwed on the alimony though. $400 a month for 10 years if I remember correctly. I know for a fact about the $400 part, just can't remember the time frame for 100% certain. I've been working with him for 11 years and he's been paying for the majority of the time I've been here and he says he has 2 years left. He makes around 60K. I don't know how he does it.
Unfortunately when you marry the girl you also marry the state of Oklahoma, and she can be a cold hard bitch.
I'm hoping your post was written out of anger and haste and that you can work things out with her. They are all crazy.