Please don't have your own affair! I had the same thoughts last year when I confirmed my H's affair.
I decided I would NEVER stoop to that level. Why would I want to be as disgusting as him? If no one else respects me, at least I do. It is important for me to lay my head down at night and know that I never did anything to feel bad about. The upsetting thing is that he calls from work me 5 times a day now. I think he is afraid I will cheat on him! Yes he deserves that, but I am the better person in this situation. When we were married 25 years ago, I took those vows seriously. Sadly, he doesn't even remember them.
Give yourself time. If you go down that road, you will be just as bad as her. Then you will hate yourself. I am so sorry for your troubles.
-mermaid-