I would call it a bad habit, which is behavioral so more of an addiction to me. Obsession is all/mostly in your head and thinking. Yours started when you were very little and you do it because it feels good. I had a symptom like that from when I was 2-3 and it took until I was 52-3 before I worked through it.

I would accept that you have this symptom for the moment and look for "cause"; I don't think you can make it go away all by itself. Sounds like you got stuck in comforting when you were little, refused to deal with the other stuff in life.