In pain,
I am sorry this is happening to your marriage, you came to the right place though.
First, know that we have all been in your shoes and we have all felt the pain, sorrow and indescribably feeling of hopelessness and lonliness that you are feeling. But there can be a bright side, there are for so many, especially those who come here and commit to making their relationship better. The goal you need to keep focus on is what you can do to win him back. You have both done many wrongs to get your marriage to where it is today. "wrongs" are subjective though, what is not wrong to you may be wrong to him, even if it is perceived by the majority to be right. What he thinks and feels is what counts, just like what you think and feel counts.
Using the analogy of the Love Bank, he has fallen in love with the person who has made the most deposits in his love bank, the OW is that person. You have made too many withdrawls and not enough deposits. He has likely done the same too you, it is not a one way street. That doesnt mean you are the cause of his affair though, you are most definitely not, but at this point none of that matters. What matters is that you make more deposits to his love bank than anyone else in the world. Dont expect results instantly though, your relationship with him 16 years ago took time to develop and his relationship with the OW took time to devlop. Your "new" relationship with him will take time to develop as well. Not only develop but it also needs to overcome the competition. I know this is a harsh way to look at it but this is a drastic situation that will take drastic measures to repair.
My appraoch was to make life changes. I knew I had certain personality traits, habits, etc that she didnt like. In order to change what needed to be changed and in order to make those changes permanent, I had to change my whole life, how I saw things, how I appraoched things, etc. I mean everything from opening the car door to putting down the toilet seat to showing respectable affection to slowing my life down to letting things slide that bothered me to stopping drinking to making dinners to giving rub downs to follow chirst and so on and so on and so on. I have even pulled away from my circle of friends and sought new cirles in a christian environment.
I am like you, I love my wife more thasn life itself and I can not imagine living life without her. I cannot imagine my children being raised in a broken home either. I want the bottom line. The bottom line for me is I want my wife and I want my children and I want a functional christian family life. I will do anyhting to get that, regardless of who is at "fault" for attempting to destry that. It sounds like you want that too.
God Bless.
2LLP