You are just a victim as his wife. Stop drowning yourself in an endless emotion of regrets. These people have moved on, you too deserve to.
I know betrayed wives have every right to be angry. It stings when the one person you trust betrays your trust. But what I don't support is trashing the other woman for the men's lack of respect.
I don't care what biology says about men and their libido. Women can cheat too but when they get married, they respect that vow. They resist all urges from outsiders because they value their man and their dignity. If these betrayed wives don't release that by blaming the other woman they encourage their husbands to continue cheating, then they should know it now.
Secondly, I believe the responsibilities vested on married women is patriarchally induced to keep woman vulnerable and unloved. If the same responsibility were imposed on men, we would have less infidelity in marriages.