Time to let my infatuation go...

My infatuation.... how many years have we been going back and forth now? He's lived in Maryland ever since he moved back to be with his mother. Came back to visit once, and we had a great time. That electric powerful connection you read about in romance novels, that's what we've always had. He's talked about moving back to Seattle, and constantly tells me how much he misses me, all the while, he has been dating someone for several years now. He's recently informed me that he is going to propose to her soon. That it's hard for him to tell me because he knows it will hurt me and it will mean that we have no chance at reuniting. He keeps updating me. "I think I'm going to propose really soon. I've had the ring for a while now." I wonder if he realizes how much it actually stings to hear this? There is no possible way that he and I can have a healthy friendship while he is engaged/married. It would just break my heart. Is this the breaking point where I need to cut ties for my own sanity? I can't keep hearing about how he constantly thinks about me all the while knowing he will be a married man soon. Very disappointing, but the right thing to do is to let him go, I know this. It's not easy now, and I don't know if it ever will be. Such is life.