Is this limerence?

I have intrusive thoughts about the guilt and shame I have about a relationship I had as a teen. I’ve been in a relationship for many years and still get triggered by my past and feel bad about it. I don’t miss him, I don’t want to be with him, I haven’t even talked to him in over 8 years but my head wanders and takes away thoughts of my current relationship. Is this limerence? How do I get rid of these thoughts if it’s been so long? I feel like I can’t enjoy my partner sometimes because my head is in the past and I feel like I can’t get married or move forward with him because I don’t want to think of my ex during those times. Please help.