I hate to depress you but, my kids have terrible sleep habits. My son is now 9 months and was sleeping through the night at 3 months. He now wakes up 3 and 4 times. I feel like I can't even function from the sleep deprevation. But, my daughter who is now 3 started sleeping through the night finally, 2 weeks before the baby was born. I haven't had a full nights sleep in over 3 years.
On the more helpful side, I have found, the more they sleep in the day the better they sleep at night. I mean regular naps! My 3 year old takes 1 nap and my 9 mo old will sleep better at night if I can get him to take atleast 2 naps in the day. I think they get overly tired and then they can't sleep and that's what keeps them up.
Hope I helped...if not atleast you are not alone!
A.