Feeding to sleep

For the last two months or so my baby (5 months old now) has almost exclusively gone to sleep while breastfeeding. By that I mean bedtime at night, nighttime wake-up soothings and daytime naps. It’s like it’s the only thing that will make him relax enough to fall asleep. He doesn’t respond to just being held, rocking or anything else I’ve tried. It has to be the boob in his mouth till he is asleep. The only exception is when he is in his pram during the day. My question is; what can I do to change this? I want to be able to have my SO take a bigger part in bedtime. I also think that the reason my baby still wakes up so often at night to eat is due to him not knowing how to put himself back to sleep as well. Any ideas welcome. 🙏