I think you may find Albert Ellis's work valuable (he founded the Rational Emotive Behavioral Therapy process, a cousin of CBT). He discusses self-esteem a lot

I think you may find Albert Ellis's work valuable (he founded the Rational Emotive Behavioral Therapy process, a cousin of CBT). He discusses self-esteem a lot in his work, particularly around the risks of both low self-esteem and high self-esteem. You may also find meditation helpful--particularly some kind of light noting practice (perhaps not Mahasi-style noting, but Shinzen Young's Unified Mindfulness/See Hear Feel technique). Deconstructing emotions and thoughts into their constituent parts not only will allow you to see your patterns more clearly, but breaking a complex emotion down also makes it more manageable to deal with. As with most habits, you'll get most out of what you're willing to do not only during therapy sessions or formal meditation sits, but during every day life.