What about an email. Don't say,"I want you back". But, let her know that you loved being with her, and you're thankful that she was a part of your life. Apologize for anything you need to, and ask for her forgiveness. She may respond, she may ignore. But, it's not going to be worse than where you are now. It hard when a OM is involved. She may still be in "honeymoon" mode with him. And, it may take time. Yes, often these relationships don't work out. It takes patience to wait it out.
Me 36 Husband 35 D5 S2 separated: 10/29/07-present Served divorce papers 1/22/09 "When the world gives out beneath your feet, it is time to learn how to fly."