Help please, im 15 very shy never had a girlfriend!!?

Please help me I am a very shy person and im so shy (scared) of girls, I don't know what to do, all my friends at least hang out with girl, but I can't. When ever I get next to a girl and talk to her, my eyes get all teary I get shy. Please teach me some tricks how to deal with shyness, and please no answers like don't worry ur still young. Its just sooo embaring, every time my friends call me to go chill, I have to make up an excuse and not go, even though I really want to.