you may not have found better, but for the 2 months that you had the affair, and the fact that you left the marriage (of how long?) based only on those 2 months, indicates that at the time you DID think you had found better. Why would you have thrown your family away if not? Dont tell me blindness or weakness, that doesnt cut it. At the time you thought it was the best choice, and that is going to cut to the quick for her.
OF course she would have known that after 2 months it was just lust, that you couldnt possibly know that this OW was your soul mate (and we know on MN that this is a paultry excuse for people behaving badly, soul mates do not exist) she would have known that the OW was all fantasy, that when Real Life kicked in, it would lose the thrill of the forbidden fruit and the everyday and little habits would not be so appealing. But still, you made that decision.
You say the affair lasted 2 months, was that 2 months since you had sex, or was that 2 months since you met. Unless you are in the habit of doing the pub/club scene it is unlikely that it started as a drunken ONS that carried on. (And if you ARE still in the pub/club scene, do you really think that was healthy for the marriage, for a man with children?) In which case there had to be a lead up, an emotional affair at least (maybe at work??) that moved across the boundaries? Why were you not able to see that you were getting into dangerous territory? Are your boundaries loose or do you just enjoy the ego flattery? Just Good Friends by Shirley Glass is essential reading if this was a friendship that you decided to take too far. If the OW is a work collegue what have you done to address that - moved jobs? looked to move jobs? Or are you kidding yourself that your wife will accept that 'its over' and trust you to not have any contact, or to keep that contact professional.
Because trust is the issue here. For those 2 months and before you broke her trust. She thought that she was happily married and you held information over her that didnt give her the right to know what was going on in her life. You lied. If your marriage wasnt happy, or you were not happy, why did you not talk to her? You broke her trust there too, because you didnt trust her to help you to solve any problems, you just chose an easy distraction. She will now be looking back at the marriage and wondering what else you lied about. About her memories, which she thought were happy, and questioning whether all was as it seemed.
How long were you married and how old are the children? Is she run ragged taking all responsibility for running the home and the children and you feel neglected. Did you take an equal part in the responsibility of your children, were you fully engaged in family life or were you, like most cheaters, leaving all the shit work to her and sulking because they were taking all the attention from you? Was that building resentment from your ex wife? Had she given up work and felt undervalued for what she did? Did you really understand all the sacrifices she was making to allow you to just carry on with your career unhindered? To provide for you? No wonder she felt rejected when you walked out for a new, probably unencumbered, bright young thing who was free to have fun and good times with you. Do you understand all that?
When you have given up a huge amount to have children (because ultimately a man can, and does, walk away, leaving you to provide for them until adulthood) possibly lost any chance on the career ladder, possibly made yourself financially dependant upon your husband if you have agreed to be a SAHM (and risking only to be able to get low paid pt work if you try to go back, due to childcare issues and a career break) you leave yourself very vulnerable, and you have to TRUST your husband implicity.