You're not doing anything wrong, it just doesn't seem to have any real therapeutic purpose and leaves you feeling disappointed and sad. You know you deserve more than this and can get it from other places. Is tht part of he appeal to you, that it's a challenge? I don't mean that in a negative way, I just know that some people are motivated by the challenge the thrill of the chase. And once they've finally won that person over, this person suddenly become much less appealing. I've heard that this sometimes happens with people who fear getting close and intimate with others.