I'm married, fell in love with a 15 year younger woman who has a boyfriend

I'm 43 and have been with my wife for 19 years. 11 of which we've been married. Our marriage has actually been over for a few years but for some reason we've just avoided the obvious for too long.We just carry out the monotonous day to day routine with our daughters and jobs. There's certainly no future for us. A year ago a new colleague caught my eye. She's 28. We connected like nothing I've ever experienced in my life before. I'd actually say we're soulmates. It's unbelievable. Despite her knowing I'm married and her having a boyfriend we fell in love. She was very hesitant about cheating and being intimate with me but I never put her under pressure. But she did end up letting herself go and we had wonderful romance. However she also loves her boyfriend. 6 months ago she got accepted to a film academy for a 4 year study program. Last week her and her boyfriend moved 200 km away. She had said she wanted to stay in touch and meet every once in a while. During their move she had a breakdown and felt overly guilty for cheating on him. She did not tell him about us. She says it'll be over with him if she does. Now she wants to fight for her relationship with him and try and mend the guilt feeling she has. She wants to give the partnership with him a fair chance. She says she can't meet me anymore but wants to stay in touch. I told her it makes no sense in me writing beautiful things to her or telling her that I love her. She'll never be able to concentrate on him and I'll just feel used. However, for some reason I can't just tell her to hit the road. I Love her too much. She's the woman of my dreams!! I'm so frustrated since the whole time during the affair I was the one always been conscientious about her feelings, making sure nobody would find out. Now she's gone and I'm the one alone here, fighting my sadness but also not knowing if I should just break off all contact with her or stay in touch and hope that someday she' ll come around, leave her boyfriend and give me the chance I deserve. Any ideas, suggestions or advice? I'd be happy. Thanks.