Have you ever changed yourself for the better?

Today was a rough day for me. I had my best friend tell me I tend to make fun of other people, my dad tell me I'm quick to judge people based on what clothes they wear, how rich or poor they are, and what they look like. I've been thinking about it all day and I finally came down and crashed. Was crying and everything. I talked it out with my mom and dad. I think the reason I do those things is because I don't feel confident about myself, and I'm insecure, so by wearing those brand name clothes that the skinny, pretty girls are wearing it makes me feel that I'm not fat, and in-style. Also, I make fun of other people to make me feel better about myself, which is a very bad way to do that. So, I've decided to change myself by start building up confidence and noticing the good things about me instead of my flaws, so I can start treating other people better. I never knew I was so mean to people like that, but when I heard it come out of my best friend's mouth, I knew I had to change. This question is just really meant for you to answer in maybe a way that you have changed yourself for the better, and if you think that people really can change themselves or if they're always the same people no matter what. Thanks for your guys' opinions! (:Have you ever changed yourself for the better?
I have not.

You are mean at times.