I previously posted a reply. It decided it was way too long. I'll give the much shorter version of the same thing here. I'm going to be blunt, but my intention is to help you see what I think is really going on.
You are in a codependent relationship with your wife. That means neither of you have the maturity or self esteem right now to be in a healthy relationship with each other - or anyone else. Both of you have poor personal boundaries. Her spending the night with the other guy and on a whim, you seeking other women during this drama with her, and her reluctant interest in you only after you found someone else ( ie. what do you mean intense?) clearly demonstrate that.
Adding other people to this mix, whether someone for you or someone for her, will exponentially ( 10x at least) increase the drama. It won't solve it. Her new relationship will fail at some point in the future (codependence there too). She may want to come back to you then, but she will not have anything stable or loving to offer you any more than she does now. She won't be coming back to give anything. She'll want to get relief from you from the pain that developed with him.
Codependent people don't know how to love. They only know how to try to grab energy from others. The only real solution here is to let both of these women go. Stop chasing women. Get yourself emotional stable and healthy before you get involved with anyone else.
Codependent relationships are a roller coaster ride of highs and lows. There is no stability to form a healthy relationship. The highs are not love or self esteem. The lows cause people to seek out others for relief. If you decide not to work on your low self esteem, you will stay on the roller coaster.
Do you have the courage to let these two women go and learn to love yourself? If not, your going to stay on the roller coaster.