Hi, abbeyrd80, welcome to SI. I am so glad you found us, all of us have walked in the very emotionally painful shoes of infidelity.
First thing I notice in your post is that you *think* you drove her to an affair. Stop that right now, she is a grown woman, she chose to cheat. Yes, you were not the best attentive husband and she did try to communicate with you, but she had other avenues...counseling, trial separation, suggesting divorce. No one makes another person cheat, that's all on them.
I suggest you get yourself into counseling. These mind moves suck. I am nine years out from discovering my husband's affair, and on occasion when I am not mentally active, those thoughts still come flooding back. For the time being, redirect them as much as possible. Do you exercise? If not, get started, join a gym, walk, run, ride a bike. Exercise does help.
Also, don't ever compare yourself to her affair partner. He could have been ANYONE. It was not about him, it was about what's broken in her. She was enjoying the attention, he could have been the guy at the grocery store. Anyone who would have given her the ego kibbles.
You deserve to ask questions, even at this late date, as you deserve the full truth. I don't know or I don't remember are not answers. Inconsistency is not a good thing either. Many cheaters try to minimize or protect themselves so they don't look so bad or think they are protecting their spouses by hiding the ugly truth.
Have you checked out the articles in the Healing Library? Get started, chock full of great information to help you process this nightmare.