Is love a more physical (neurochemical) process than emotional reaction?

Some people say that once you know that your lover isn't worth it you will get over it. It isn't the case for me.

I got a weird experience that I still feel very sad even after I have identify my love as an unworthy person a year after breakup. Specially when I look at the pictures we had before. That evil face once I loved dearly.

All the details that I didn't notice kick in. I realized how cold-blooded and selfish she was. The horrible things she did. Cutting words she said. How monstrous she left me in the dark to die, while she moved on to meet her new "wonder". How unrespectful with her stupid, colour-changing lies that she made up and I even fell for it. And I know that she isn't good even as a friend. Person like her probably will fail at any long-term relationship.

But when I'm not objectively viewing the past, I still feel very hurt as if I lost the most valuable person in my whole world. Is it because the attachment physically exists in my brain?

I still hold the "love no matter what", "only death stops the love" quote. But I don't even want to get back to this doomed relationship because I lost much. Any explain?