My daughter Baby J is less than a week short of 7 months old. She doesn't sleep. Well, of course she sleeps, but in no predictable pattern and never more than four or five hours at a time. For example, last night she did her impression of a snooze alarm: asleep for 4 hours, then 2, then 1, then 1 more. And that was a good night!
She also won't go back to sleep unless she's fed. I know all the books say that this is my fault for not being firmer with her, and they're probably right. But I have to look at my own short-term survival. If I feed her when she cries, she'll go back to sleep and so can I, even if it's only for a couple of hours. If I don't feed her, I either have to walk around with her until she settles again or try to ignore her crying. Neither of these has worked because she's amazingly stubborn and single-minded. I eventually give in and feed her, having not gotten any sleep in the meantime.
I've been trying to keep her awake during the day. She's also starting solids, so I'm feeding her that fairly late in the evening. Objectively, neither is really helping, but they do make me feel slightly more in control of the situation.
She gets this from me. I'm almost thirty and I don't actually sleep through the night either.