Obsession: A persistent disturbing preoccupation with an often unreasonable idea or feeling.
Compulsive preoccupation with a fixed idea or an unwanted feeling or emotion, often accompanied by symptoms of anxiety.
A compulsive, often unreasonable idea or emotion.

I just attended a codependents anonymous meeting for the first time this week.
So, yes I have constantly confused love with obsession throughout my life with my parents.
They were both alcoholics while I was growing up, (still are).
Growing up, I was constantly confused and hurt by their ability to put alcohol first over me. I knew that my mom's drinking was related to her deep sadness (depression) and so I thought if I could make her happy, then she would drink less and be there for me more. But.. I confused my "making her happy" with love. I became hypervigilant, obsessed with watching her behavior to see how she was feeling so that I could offer a solution to her problem of the day, make her laugh or cheer her up. This was not love, in retrospect it was was indeed a "a persistent disturbing preoccupation with an often unreasonable idea or feeling" - that I could fix her, lessen her pain, lessen her drinking and change the situation so she would be more present and available to me. Today I struggle with this, confusing love with a need to fix others' problems.