I excepted a sexless marriage...
Are you still in a sexless marriage, because I suspect all of your problems trace back to this fact.
Yes she found porn on my phone....I looked up exes on Facebook. Never once did I reach out to anyone....
But, I'm sure you thought about it (and I don't mean that in an accusing way).
These are coping mechanisms men use in a sexless marriage. Porn (and masturbation) provide the physical release you wife won't give you. You build a fantasy life in your head of "what might have been" if you had married one of your old flames instead of your wife; you may not act on it, but it gives you some mental relief from your current situation.
...grabbing my phone and excusing me of deleting my history as soon as I walk in the door.
Some part of her realizes she is about to lose you (and she is). But, she is attacking the symptoms of the problem (the porn) instead of the root cause (your sexless relationship).
I am tired of working a hard days work... I go to work and I come straight home. I have NEVER cheated on my wife. I will live with that I was a good husband...I am a great father. Here is a woman for six years who...put work and school ahead of me. I...support[ed] her dream to become a nurse.
You were the typical "nice guy." Nice guys rarely do well in marriages.
You can blame me forever for destroying your self esteem...
This is called projection. She has done something in the past to destroy her self-esteem, and she is blaming it on you. Ignore this.
We both know what you did while pregnant with both kids. I can forgive you for that.
Obviously, you can't or you wouldn't bring it up.
But you holding this BS over my head too long.
Again, your porn viewing is a SYMPTOM of a deeper problem--a sexless marriage. When she gets after you the next time, just reply "If I wasn't in a sexless marriage, I wouldn't be tempted to look at porn."
Go through some of the threads here on sexless marriages and nice guy syndrome. I would wager you are suffering from both.
You are probably doing the right things. Shaking things up so she understands your marriage can't go on this way.
BTW, I understand your wife being concerned. Her marriage is headed toward a rocky time. But, she is taking the wrong approach to fixing it. The porn is a symptom of another problem. As long as she focuses on the symptom instead of the cause, her marriage will get worse.