How bad?

How bad is my self- esteem if I cant wear my hair up to school. Cause this teacher keeps telling me to put my hair up but I havent put my hair up for 5 years! I have alot of other life problems which I wont go into now to. I want to that I might I have headlice which I dont because I dd my hair today and nothingcame out soyeh. Is my self- esteem really bad and how can I fix it? This is just an edit thing below on explaining how hair up relates to self-esteem

When you dont have the confidence to do something or try something new you get upset because you cant do it when you should be able to. I should be able to put my hair up it isnt hard. Everyone else does but me.
I try and try but everytime I do put it up I quickly take it down cause I am afraid of what people will think and of what the ywill say. If your a person who cares about wat people says then you get hurt easily and so does your feeelings. I Dnt have the confidene to where it up when I shoul and everyone teases me cause of that :( which effects my self-esteem alot.

I have had a similar problem. When someone told me to do something, which I haven't done before, I would fall into a deep cave of thinking. What would happen if I do this? How will my friends react to this? What will the people think about me?
These are just our foolish assumptions. Nobody in the world has got so much time to just think about you, just note what you do and how you do and just look at the very detail of your actions. Everybody is busy in his own life. Nobody cares about what you do or how you do it. So my suggestion is "just do it". You will quickly realize that bringing a change is not that difficult.

I agree with ahsankmc. Do you think anything different about your classmates when they change something in their appearance? We all focus on our own image far more than the people around us pay attention to what we do.

A good method for judging what is important is to ask yourself how much difference it will make in your life five years from now. So who will remember whether your hair was up or down on one particular day? Other people sometimes make stupid comments on how you look but they are meaningless.

What you put inside your head will make the difference in your life, not how you arrange what's on top of it.