Getting married next year and...

Can't stop thinking about another guy. All through high school, college and beyond, me and this guy were best friends. We always had something more going on but never admitted it to each other. When I was done college he told me how he felt and wanted to be together but ended up moving across the country and I moved home. I reconnected with an old friend from the same group and we've been together for almost 5 years. We have a daughter together and are getting married next year. Now I can't stop thinking about the other guy and what it would be like if we had gotten together.