Am good-looking, so why don't I have a girlfriend!

Am good-looking, so why don't I have a girlfriend!

Dear Diana,

I am an 18-year-old good-looking guy. I become the centre of attraction wherever I go. Many girls get attracted to me and flirt with me but when I reciprocate it doesn't materialise further and fizzles off. Something goes wrong every time. Some say I am too childish while some break it without an apparent reason. I like laughing and making people laugh but I may overdo it sometimes. I have tried a lot to become serious and reserved but that's just not me. None of my crushes have ever gone to the next level. Had I been an average looking guy, I would have consoled myself but being a guy with good personality and looks and not having a GF really hurts. I need a companion. Maybe I am too childish... I have had a lot of trouble in other areas of my life due to this flaw but I can't get over it. Is this really the problem? Do I need a change in my personality? I am lonely and need help!