You need to break up with him. If I were you, I would wait a couple weeks and see how it goes. Try to make an honest effort in the relationship, because who knows? Maybe you'll end up liking this guy. If not, then just tell him it's not working out or something. But if you really don't like him and see this going no where but down, then just tell him the truth, that you were surprised when he asked you and wasn't really thinking. Try being as nice as you can about it though. Just be sure not to lead him on. :)
I hope I helped!
Thank you so incredibly much! (: you've been a great help!!! Yeah, I think I will break up with him because it just feels awkward... You know? But yeah thank you so much!!!!!
I hope I helped!