Ok,I have a problem..I think I might be in love with my best friend,what should I do?

I like my best friend,alot! I think I might even love him.I talk to him everyday online and when I’m not talking to him,I get sad.He makes me happy when I’m upset and even when my friends try to cheer me up,my best friend does it better.My friend introduced us and we instantly became friends.We can talk about everything and we share secrets also.He even tells me things his friends,even best friends don’t know.I think he likes me back and all my friends say so.I haven’t really felt this way about any guy before and I’ve liked alot of guys in the past.I really don’t wanna loose him but he’s a little shy about things so i don’t know..What should I do?