Toddler sleeping

Howwwww do I get my 15 month old to sleep through the night?! I breastfed him, so I think that is a large part of the reason for why he doesn’t sleep all night. He’s used to the contact and me feeding him at night whenever he woke up. I stopped middle of the night feedings whenever he was 12 months hoping that would help and so far it hasn’t. I have to pat his bum and give him his pacifier to get him to go to sleep. I’m not a fan of CIO so any other suggestions would be helpful!