I'm making this comment assuming what you're saying is accurate. I'm not making a judgment on whether or not it is.

Probably the hardest thing is that when I argue with my wife she always threatens to kill herself. I literally can't say anything critical without a huge fight. She has turned her family against me, and attempted to turn my parents against me. She's also tried disclosing very personal information to my family that I don't want them to know (my childhood sexual abuse). She's pretty much destroyed my confidence. Tonight she has run around the house with knives threatening to harm herself, threatened to kill herself.

Read that. Pretend I said it. What would you want me to do?

Since you can't talk to her, I'm assuming she's unwilling to do therapy or psych evals? That's like the last thing you can use in this situation. If that's not possible, the only other option is separation, my dude.

This isn't a case of reddit making a big deal out of something small, that's like, textbook. She's making threats of violence, yes to herself, but she's not emotionally stable, to the point where she is a physically dangerous person. If her family is at all sane, they need to be contacted not with a plea for help but to be informed of her behavior and the fact that they now have to deal with that.

Ultimately, what she does if/when you leave her is not your responsibility. A spouse/best friend does not turn people against their spouse/best friend, nor share their secrets. She's already broken her vows (with her actions, her sexual orientation is perhaps more complex), your moral obligation has been annulled. You sound like a prisoner.