Tips on how to make 4 month old sleep longer

Ds2 has been waking 3 hourly since birth. He is now just shy of 4 months old and I'm at the end of my rope. He is exclusively breastfed and is initially put in his cradle to sleep and at some stage of the night I generally bring him into bed with me as its the only way I can get some sleep to keep up with my 2 year old during the day. The co sleeping was going well but lately I have been in so much pain from sleeping in one position all night and most nights I'm hanging off the side if the bed as he has all but kicked me off the bed lol. I really need to get him to sleep longer in his own bed but really don't know what to do. Any tips on how I can get him to sleep for a longer period overnight?

I dont know but here's a big :hug: which i know is going to do nothing to help him sleep sorry.
Maybe he will just eventually grow out of it. I know that my ds was a dreadful sleeper and was still waking 3-4 hourly until he was 13 months old (probably something you dont really want to hear). All i can suggest really is do you have a night time wind down routine? Is he waking and wanting to feed? Maybe you could try to dream feed if that's the case?. What about one of those little bed thingys that you put in the bed with you to co-sleep so he can be with you but you get your own space IYKWIM? or can you put his cot next to the bed with the side off.

Good luck and i'm sure it wont last forever, :hug: