You acknowledge that you treated your wife (and others) in an arrogant and impatient manner. It's probably been a very long time since anyone made your wife feel important or special.
Apparently, this young man is currently meeting your wife's unmet emotional needs for attention, admiration, and conversation. He listens to her, empathizes with her feelings, and makes her feel good about herself.
She's searching for happiness--and she's not going to find it in her marriage with you unless the two of you start over from scratch and begin to build a better marriage.
For the tools to build a better marriage, I suggest that you examine the articles on the marriage builder's website:
http://www.marriagebuilders.com/