I made a decision to "love" my girlfriend. I don't really know what love is. Someone told me once that love is a "genuine care and concern for another". If that's the case then I love her.
I act "as if"... treating her with kindness, respect and appreciation. Two years and counting and so far so good.
I don't think I'll ever feel a "deep attachment that two people can feel with each other" but if what I have is as close as it's going to get, I'm okay with it.