Sleeping....what's that?

Harrison's sleeping just seems to be getting worse and worse and I'm running out of ideas. He goes down really easily but then will wake up sometime between 3 and 5 hours later...and at first just needed his binky to fall back asleep..but then we got sick of going in there eighteen times a night (and what felt like every five minutes) to put the binky back in so we tried to not give the binky back and he just cries and cries---nothing will console him but the binky. So we give in (after waiting awhile, going in, consoling, waiting, trying to console..)..and then last night ...he cried for over an hour WITH the binky (like he was preempting us taking it away?) until I fed him...I'm sure he's ridiculously confused and nothing seems to be working. I know with babies you need to be consistent, etc etc...Oh yeah and all three of us have colds which I think have been exacerbated by the lack of sleep. I've read, I've talked to people--apart from letting him cry for hours (not just because I can't handle it..the more practical reason, neither cory nor I can spend the sleepless nights it would cause...) advice??? I know at five months he SHOULD be sleeping through the night no problem and yet he just won't do it.