First thing is to improve yourself. Like yourself more than before day by day and you will feel difference. Self-esteem is related to the internal confidence that someone has on him/herself.
Strat praising yourself......but in a positive way - try to find out your key strengths and then weaknesses. Point out or even write down in a ranking who actually you are....what are the areas you are good and whar are your weak points...
Then instead of wasting time on eliminating your weaker points start sharpening your strengths. Everyone has some God gifted abilities that can't be skilled. So just thinking on how to eliminate weaknesses is a wasting of time. sharp your strengths as like, these becomes your keys of success and hide your weaknesses. This will lead to increase in your self-esteem.
Always think on letters; I will, I do, I am responsible, I have the ability, I never stop, I never lose hope, I must struggle, its my dream, its my passion.
You know praising oneself is an art - if you would liked to become more lovable or likeable 10 % more, start praising yourself 15 % more than before. Make your habit to spend time in front of mirror. Talk to yourself.
Develop strong emotions that further lead to the desired passion that define your destination- give you success.