"So" vs"Too"

[belly_ttt]

Could you tell me the difference between "so" and" too"?
ex: I feel so sleepy or too sleepy?

[Hi_there_Carl]

I feel too sleepy (to do something or go someplace)

I feel so sleepy - can stand on its own or use it like this...
I feel so sleepy I think I will go to bed.

[blouen]

How about :
I am very sleepy.