Hi H.,
I have a 15 month old daughter, so it seems like it has been an eternity since I have had to deal with the sleep deprivation, but I can tell you that babies can and do sleep through the night at that age. My daughter was breast-fed and she slept 8 hours per night for the first time at 5 weeks old and by the time she was 8 weeks old, she was sleeping 10 hours per night pretty consistently. Now she sleeps 11-12 hours per night (and by sleeping through the night, I mean she never wakes up and cries at all). While I don't think this is necessarily normal and certainly doesn't happen with all kids, you can get your baby to start sleeping at least a little longer by doing a few things.
First, you should try very hard to feed them more often in the evening hours and close to bedtime (we used to put my daughter to bed for the night at around 10-11pm when she was that age). This way, you know that they have had plenty to eat and shouldn't "need" to eat again in an hour. Now, this is where the tough part comes in. Even at 6 weeks old, you have to be able to let them cry for a few minutes at a time to see if they can get themselves back to sleep. That doesn't mean ignore him or starve him, but try to give him a couple of minutes after he wakes up before you run right into his room (or to the bassinett if he is still in your room). If you do have to go in there, try rubbing his tummy or back to calm him without picking him up. If he uses a pacifier, put it back in his mouth and try to soothe him until he calms down or falls back to sleep. It may seem like it would be easier to just pick him up and feed him at the time, but a few nights of this routine can save HOURS later on when they expect to be fed in the middle of the night at 6, 8, 10 months old because that's what they have always gotten. If you have tried to soothe him and he is persistent, then you may have to feed him. (Also, if he has slept for like 3-4 hours and wakes up, then I would think you may need to feed him...I'm just recommending self soothing for the every hour or two wakeup when he should't necessarily be starving)
Second, if you haven't moved him into his own bed yet, I would do that. You will all sleep better (even your sleepy head husband), if you don't hear every little noise each other makes. This is especially true for the mommies because as I'm sure you've noticed, we hear everything and daddies hear very little. My peidatrician recommended moving my daughter to her bed at her 1 month checkup, and I honestly believe that helped a ton! My husband snores and I know it can keep me up, so I am certain that wasn't helping my daughter sleep through the night either.
I have to say that it is excrutiating to listen to your baby cry in the middle of the night (even for 2 minutes and I used to time it on the clock!), but I firmly believe that using these techniques helped me teach my daughter how to get to sleep on her own. Even now, when she wakes up, she will play in her crib for awhile before she calls for me to come and get her. So, please don't worry that you are creating a negative connection with their bed and that they won't want to stay in it if you keep them in there crying for a few minutes. My daugher willingly goes to bed (even asking to go to sleep when she's tired) and plays in her bed when she wakes up.
I know it's not easy to be deprived of sleep and I also know that feeding the baby seems like the easiest way for everyone to get some sleep, but if it has only been an hour or two since the last feeding, then you know you aren't starving your child if you try to get them past one of those wakeups without food. And, as he gets older, he should naturally be able to go longer between feedings anyway. Best of luck to you and if you want to send me an email with any questions, I would be happy to help. (____@____.com) I promise it gets easier!