I suffer from low self esteem and low confidence. It is included in the document I received when I was assessed and diagnosed with Asperger's.
For me, it's not from being picked on or bullied, but from always feeling that I'm not living up to my potential, chronic underachievement, not measuring up. Other people have even pointed this out, but not in a mean way. I know I have abilities, skills, talent, am reasonably attractive, healthy, fit and have a high intelligence, so why am I always struggling, feeling less than, accepting of substandard conditions?
Yes, it has made me feel like I was not good enough to pursue relationships with people I found attractive, it has kept me from taking opportunities. While I know that it can result from how we are treated, it can also come from an internal negative assessment of oneself.