Pacifier question

My baby is 6 weeks old and started taking a pacifier. For the past month he's been waking up very often. I would feed him and put him to sleep and he would wake up in 30 minutes up to an hour and a half later and start crying, looking for my boob. Every time I feed him he takes his time and eats a good amount so I don't understand why he would wake up 30 minutes later asking for food again? My nipples are starting to get sore from this kind of feeding so we gave him a pacifier and so far he's been using it. Well my question is, if I feed him and he goes to sleep and wakes up 30 minutes later looking for a boob can I give him a pacifier? I don't wanna give it to him if he's actually hungry. And also, when he's sleeping with a pacifier and it falls out he doesn't stay asleep but starts crying right away until I put the paci back in his mouth. Is it because he's hungry and I should feed him?? I just don't know 😩