HELP URGENT!? what do i do?

The kind of guy that he seems like would think it was cute that you got tongue-tied. It seems to me that he likes you, from what you say. I think that the day he leaves, you should tell him, if possible. Or at least the last day you'll see him. Don't confess deeply, just tell him you've "kinda sorta" liked him for a while, and will really miss him while he's gone, and (if you want), that he should keep in touch!