What's this?

I totally forgot my ex-fling. I don't have any feelings for her anymore, and thinking about her never makes me sad. From time to time, I remember her, but I feel like I'm forcing myself to think about her. I don't know why, but I can't let go of people in my mind. It takes me so much time to stop holding onto their ghosts. I can't wrap my head around endings. Death and breakups feel the same to me. What could be the reason for this? I know that I'm fearful-avoidant. I might have inattentive ADHD, and I might have relationship OCD. Is it because of relationship OCD?