BC,
Would it be possible to transfer your obsession with this man to your recovery? Put all the energy that is going towards him into focusing on yourself?
My situation was a little different but at around 3-4 months I was pretty eaten up with wanting to know where my marriage would end up. I was hyperfocused on my wife. It was suggested that I let her do her thing and just focus on myself and my recovery. I did and it was what I needed to do. Where I ended up after a year of hard recovery work was very different than where I started out. I changed and my priorities, perspective, etc... changed.
Perhaps you could pour all of this energy towards recovery?