Feeding to sleep, how can I stop?

Hi my son is 7 months in a few days and he is either fed to sleep or driven to sleep. I know it has to stop but I just don't know how! I wish it was as easy as people tell me but he won't fall asleep if I don't. I've tried and it's backfired in short 20 min naps and screaming fits until I do. I'll say, I can rock him to sleep (rare) but that's no better. Any strategies? He won't take a pacifier and he's been sooooo clingy recently. I'm trying to adjust our schedule and start sleep training but I can't if he's this persistent on me breastfeeding him to sleep:( Also, he refuses to eat as much after a nap, even at the start of the day and even if he's hungry. It's confusing and frustrating.