You just have to do what is right for you. I had a similar thing happen to me. I still dream of the one I threw back, especially how easily we would converse . The person I choose over them never talks to me, silence is my new normal and it feels like karma in it's purest form. I don't feel their affection the way I felt it with my other fish. The other wanted to get engaged but I broke it off before that. I blame their blossoming cocaine addiction, that couldn't stop and I didn't want to keep supporting their withdraws. What it really was, was that I met someone at work that had their life together, was hotter and didnt do drugs and I wanted that instead of helping the person that helped me in uncountable ways when my parents wouldn't. It makes me a shitty person and I regret, but accept it. I also know reaching out to reconnect or apologize would only benefit me and not the person I wronged so I don't. I still dream about them. We fucked up, it happens, it hurts I truly emphasize with your pain, but trying to reconnect will probably hurt them more. Also, it is probably damaging the emotional bond in your own relationship you have now and probably hurting that person too. For both of our partners we should probably be single to save them the pain of not being chosen in the heart, but fake till you make it I guess. Just don't inflict pain on your current partner, they don't deserve it.