I need help

I was wondering if anyone could help well I am tooooo shy to go up to a girl and say hi I cant do it I have tried I have tried to fix it but nothing works I am 5'7 260 I have been like this since I was about 12 or 13 but I cant do it all the girls that know me think I am sweet but I dont know what to say I am just dumbfounded I have always thought it had something to do with my weight so I am working on that please help