I need help with sleeping?

When my baby wakes up in the night, I will feed him and he goes to sleep, but then wakes up 30 min. later and he cries. I don't know how to get him back to sleep. I try to rock him, but he squirms and moves a lot and I can't hold him. I usually give in to the pacifier, but it always falls out. WHat can I do? I want him to sleep better, but he wakes whenever that dang pacifier falls out. Help me please?