i would guess the obsession is an escape. it is similar to an addiction in that you may be trying to avoid painful feelings. being in love, whether in actuality or in your imagination releases endorphins. you said you had serious marriage problems, family problems and issues from your past crop up. what is strange to me is that at the end of your post you say everything in your life is good now. i am thinking you are maybe minimizing your problems and trying to tell yourself everything is fine when it really isn't and that is why you are still so unhappy. you mentioned you thought you'd dealt with your childhood issues many years ago but they cropped up. i think you may be doing the same thing now with your more recent problems. it takes time to deal with issues and frequently is a process.