Has this boy gone off me?

I understand why you're a bit confused. I think it would be worthwhile to ask him what's up with him -- meet him on Facebook Video Chat Rounds or someplace (a href="http://apps.facebook.com/chatrounds/" rel="nofollow"http://apps.facebook.com/chatrounds//a ) and let him know that you're still interested in him. I think what might have happened is that he got a bit skittish because you told him it as moving too fast and then he probably also got sucked in by work as well. I think you have nothing to lose if you ask him directly if he's still interested in starting something with you.