I've been talking about my successes with Cogantive Behaviour Therpapy (CBT) a lot. One of the things it deals with are those negative core beliefs behind our self-worth and lack of self-esteem. With a little work, one can learn to challenge and manage those beliefs about ourselves.

It can be difficult to find a therapist trained in this (I recommend a one-on-one program). If this is the case, there are a slew of self-help CBT books out there. I recommend a work-book or book that contains charts, logs, and worksheets. Actually do the work and I'm pretty sure you too will see results.