Hello Otherworlder92, welcome to PC! I hope you find your time here to be of benefit.

This is a difficult situation to be in. It sounds like you want to break it off with this woman, so I definitely encourage you to do that. If she says she will harm herself you can always call 911 to report that, and they will force her into the hospital. There is not much you can do aside from that. If she truly intends to hurt herself, she will. But people will often dangle that in front of their partner to stop them from leaving...it's a form of manipulation.

You didn't mention if you wanted to stay with your wife. Either way, I recommend telling her the truth and letting her decide whether or not she wants to stay. For me cheating (especially for a year) would be a deal breaker, but perhaps she'd be willing to try and work things out if you wanted to. Do you want to stay with your wife?

I wish you the best of luck in addressing this and hopefully you will learn something from this.