How do I convince my daughter to leave that married man alone without her bashing MY relationship?

Tell your daughter how precious that she is, and that you respect her. She needs to know that her own mom respects her. Her self- esteem starts with how her mother feels about her, and then of course how she feels about herself. You've been through some rough times, and she needs to know that no matter how crazy the world is out there, she always has the love and support of her mother. Part of being young is making mistakes and learning (hopefully) from those mistakes. Tell your daughter that she is your hero. Tell her all the reasons why you respect her as a beautiful, strong woman. She needs to focus on the positive and that starts with you. Don't mention the negatives. Don't even mention the married man. Focus on all the reasons that you respect her. She will gain the confidence that she needs!