Low self-esteem being our focus can negatively affect virtually every part of your life including your relationships, your job, your health e.t.c. A lot of people have spent their entire life looking down on themselves. Several reasons might have caused this abusive parents, an experience from the past, loss of a loved one... it could be anything. It is actually possible to raise your esteem to a healthy level no matter how long you might have lived that way.
You can start by changing the way you think- about yourself and your life. This is essential in boosting your self-esteem. Its all in the head! no matter what others think or say, it all boils down to you accepting it or not. Decide that you would stop with the negative perception and embrace the positive.
Identify troubling conditions and situations. What is it about you or your surrounding that makes you feel the way you do, is it your physical appearance, your background, having to stand in front of people, fear of being rejected? note them, being able to identify the problem would help you solve it.
Become aware of your beliefs and thoughts of what you listed. What you say to yourself about them, your interpretation of what the situation means. they may be rational or irrational, positive, negative or neutral, based on false ideas e.t.c.
Now that you know some of what is bothering you, you can pin point negative or inaccurate thoughts and address them. Initially, it might be hard to reason beyond what you normally think but with time, you would realize that many of such thoughts are just opinions and not facts. I'm too this or that..., i'm not good enough because of something...says who? you are not the only one, people still love what you think is a flaw.
Try and list out all the things you like about yourself or what you do and dwell on those. It's easy to overlook the good for the bad, but that's an habit you would have to stop. When the negative thoughts come up, force them aside by thinking of the good things you have. Try to see the good in the bad, turn your weaknesses to strengths. It would require time but it would happen if you persist. Use hopeful statements, treat yourself with kindness and encouragement. Try to be as optimistic as possible that no matter what, you are able'. Forgive yourself on whatever issue it may be, don't be so hard on yourself. Life goes on things can get better or corrected. It's all about you being happy being you.