I dunno, I always thought, at least in my personal experience, the low self-esteem was always hand in hand with my lacklustre love life. My main issues are low self esteem and self worth, so if I actually found a girl who could love me and care about me, I assumed that'd make me feel as if I was actually worth something, knowing that I was actually attractive and worthwhile to someone, and not just a waste of space. To have those feelings continue whilst also being in a relationship seems like paradoxical.