Wow...sorry for your pain and suffering. Sounds like you don't have children, which in this case, is a blessing.
It sounds like there were some stresses in your marriage, and your wife wanted you to "man-up": regain your confidence, take interest in your appearance, find a better job. You failed to do so in a timely manner -- so she decided to confide in her boss (an alpha male who seems successful) and he steals her from you.
Here are some things for you to consider:
1. Do you want to be married to and build your life with someone who puts demands on you for change and if you fail to do so, will cheat on you? This is a major character flaw on her part. The problem with the "get-a-life" philosophy is there is no respite from it. You will always be on eggshells performing for a woman who has demonstrated that she leaves when you fail to meet her expectations. I have gotten to know 3 "successful" divorce busting men who changed their life around in order to win back their wives. It worked for a year or two. When they started slipping back in their normal behavior their wives cheated on them again and left them. They are all divorced now. For classic Divorce-busting to work, your cheating spouse needs to acknowledge how terrible she has been, how much she hurt you and how remorseful she is. In other words, SHE needs to change. Classic divorce recovery therapy like "After the Affair" by Janis Spring will tell you as much. If she is being drawn back by the "new and improved" RedHawk she will cheat again unless you remain *flawlessly* new and improved. (good luck with that). The power will always remain in her hands unless SHE really wants to fight for your marriage.
2. Stop trying to win her back. Stop inviting her back into your life. She doesn't really think she'll ever lose you: you will ALWAYS be there for her. Proceed with the divorce, move on with you life, stop looking back. When you STOP caring about what she thinks she MIGHT notice. The best "last resort technique" and "get a life" strategy is to REALLY move on, not LOOK like you are.
3. If you want a more humorous approach on divorcing a cheater, have a look at the website called Chump Lady. It's funny and cathartic.
4. If you don't have kids -- again -- count your blessings. You might actually be able to move on from this.
