The person that you've become today is the result of all the choices and decisions you've made up to this date. Every choice that you have made correctly and acted upon consistently you've strengthen your character. However, every time that you have made choices that was inconsistent with the person with what you knew to be right will weaken your character.
Your whole life is a test. It will determine what you are truly made of deep down in side. Character develops through the choices we make in our daily life and decide among the alternatives and other temptations.
When you develop and strengthen your character over time while exerting your willpower and self-discipline that's consistent with the very best you can be will have a big payoff. This payoff comes when you are able to choose the right over the wrong and the more difficult over the easy. When this happens your self-esteem increases and you like and respect your self more.
You must be able to have a long-term perspective when you are developing your character. The likelihood of you doing the right thing in the short term is determined by you thinking about the long term consequences of your behaviors. Always ask this question when making a choice, "What's important here?"
So every time you do or say something that is inconsistent with the very best values just resolve that you will do better the next time.