One of the major factors of being yourself is accepting who you are; as you are.
All the "being true to yourself" write ups are good reminders that, self-acceptance is one of the cornerstone of happiness. But, if you want to make yourself happy one of the best single way to do it is to stop having a low self esteem and be yourself.
But like all wonderful things, you must put in the effort to know yourself better and accept yourself for who you are. It can sometimes be hard to even know "who you are" and if you have been putting up a false front for long enough.
This is the sort of mental dissonance that can make people very sad, the only thing that can be of great help is when you try "finding yourself" and taking time and steps to really study yourself and your feelings.
Mindfulness exercise is one of the best ways to do with, when you do that you are far more of tune with your self and desires than when you just blindly react.