Let me start by saying, STOP!
Stop caring about what other people think of you.
I know that you want others to think the very best about you, but you cannot live your life when you constantly care what other people may think of your actions or how you look. Care about what you think of you!
HYPE YOURSELF.
People get too into trying to impress the next person, when everyone should focus on impressing their selves. Impress yourself by studying hard, keeping yourself healthy, going for and accomplishing your goals. Impress yourself by being the very best you you could be.
You do not need other people's validation in order to be happy or to have success.
Just be you, for you. Either people will love you or hate you - but the ones that truly love you will always be around. Surround yourself with positive people, people that will pick you up when you fall down. Get rid of the negative because, remember, you don't live to impress them!
DEFEND YOURSELF.
Not only should you stop caring about what others think, you should stop letting people speak negatively about you.
Someone spreading lies about you? Confront them. Someone say or do something to you that hurt you? Speak up about it. Do not allow anyone to get away with making you feel unworthy, unattractive or unsuccessful! Tell them how you feel and get rid of the negativity once and for all.
Bottom line; pick your head up, dust the dirt off your shoulders and keep it pushing. Allow no one to stop you from getting what you want in life. Allow no one to make you feel bad about yourself. And allow NO ONE to stop you from impressing yourself!