Boyfriend blames me for everything

I've been seeing this guy for 6 months. On paper, he's perfect. Smart, fit, funny... blah blah. But, in person, he can be moody as hell. Some random thing will set him off, and he'll go silent for 20 minutes. I'll ask him what's wrong, and he'll get angry, tell me it's nothing, then continue freezing me out. He also blames me for random things that frustrate him, like not waking him up at a certain time (even though he never asked me to) or just the tension in the room when in reality I'm cracking every joke I can think of to lighten HIM up. Yes, I've tried talking to him, and you can guess how he responded. So now I'm not sure what to do. Any advice?