J.V.
While I don't know the logistics here, I can tell you that my ex was a monster! He cheated, lied, abused drugs, physically abusive and neglectful to myself and our child. He was completely unreliable in ALL aspects of parenting once we split, was thousands of dollars behind on child support, would "tweak" his witholdings when he did work so I wouldn't get his tax return and disappointed our daughter more times that I can count, among other things. When I heard that he was getting married, I was a little sad.
When he passed away I cried like a baby. Looking back, I realized that he will always have a piece of my heart because we share something; our daughter. He and I created something that was, and still is incredibly important! Did I love him at one time? yes. Do I love what we created? yes. Am I "in love" with him. NO!
I think that being in love with someone and loving someone because of something that you share (child/children) can be confused as one and the same. But, its not. It's time to let go and enjoy what you have.