I truly had some of the best times of my life with my XABF. My sister told me early on that she had never seen me happier - and it was true. First six months were wonderful and the next six months so awful that it was really hard to reconcile the two.
After we broke up I found a lot of reminders, anniversaries and familiar places incredibly sad. I tried wherever possible to avoid situations and places that had been "ours."
And I really grieved. But I was grieving for something that by the end of the relationship just wasn't reality. So I made a list of all the absolute worst worst times - times he had lied, or withdrawn, or gone missing for two days only to have resurfaced after a stay in the drunk tank. When I really got stuck thinking of the good times, I pulled that list out as a reality check.
No matter how great it was in the beginning, it didn't outweigh even one incident on the worst of worst times list. It's ok to grieve for the good times - normal and healthy and part of the process. For me, keeping a written record of how things actually were by the end and how it was affecting my life really helped me to put the good times in perspective.
Hugs,
SL.