Sorry, but your wife sounds like she has serious issues. Serial infidelity is above MY pay-grade, and for me personally would be a deal-breaker.
Are you sure this is a woman of quality you want to remain married to? I don't see where she's done ANY of the necessary work -- the introspection and counseling necessary to figure out WHY she turns to sex with other men when she gets antsy, or why she even gets antsy to begin with (I'm not even seeing any serious marital issues, not that those would excuse her decisions?).
I'm as pro-marriage as anyone on this site, but personally I'd do the "let her go" thing. If she does the required work and turns her life around, you could always re-marry her (about 20% of people re-marry their same spouse, with nearly all reporting that the new marriage is better than ever).
Any other dysfunction (infidelity, addictions, etc.) she has had, or in her family?
Sorry to be so blunt, but we might as well plunge right into this.
