18 month old baby not sleeping through the night..?

So...my baby was always a perfect sleeper:he would sleep the whole night from 10 pm to 9 am.Two months ago he scared the hell out of me hen he woke up and started screaming like somebody was killing him.Went to the doctor and found out it was night terror and that it will p on its own.And it did...but for some reason he is still not sleeping.Starting with 3 am he wakes up every hour on the hour ,crying not screaming but he is up.And so am i.I give him the pacifier that is right there next to him and he goes back to sleep .One hour later he is up again and i dont understand what is going on.I am beat and falling apart.I dont understand how come i did not have problems when he was a newborn and now he is behaving like this...