How to be a more confident guy?

Hi, I'm 15 years old and I'll be 16 this coming thursday. I'm just wondering if anyone knows how i can be more confident in myself. My self consciousness and lack of confidence makes day to day life A lot more difficult then it should be. A lot of people tell me I'm cute handsome y etc. and my family is always trying to not be so hard on myself but In my eyes i see myself as ugly, likewise with sports. People tell me I'm really good but as i see it im terrible.. I just know my life would be A lot better (Not saying its bad I have a very blessed life) if i were more confident.