TorahWeb posted something recently that I've been planning on posting about for a bit; it is an essay and audio or video interview with R' Dr. Abraham J. Twerski about his struggle with low self-esteem. I think it's an important issue, and the essay is excellent (readers of his books will recognize it). I'm only partway through the video, but R' Dr. Twerski is clear and easy to listen to.
When I was in Israel, while in a rough stretch, I found that I gained a tremendous amount by reading a few of his books, particularly the ones that utilized Peanuts characters to present a message. I was able to internalize those ideas by relating the examples and messages to myself, and I have been a very different - and much better, happier, and healthier - person ever since. For those who know me, or in particular knew me then, they are probably well aware of the differences between myself coming out of high school and after that period of time in Israel.
Of course, if anyone has a serious psychological or emotional issue, they should seek professional help. Not all people nor all situations are meant to be handled by one's self.