Im at a loss here

My son is 5 month old, soon to be 6 in two weeks. He was sleeping fine in his crib up until about a week ago.

Before we would feed him before bed, and we’d let him sleep up until he woke up hungry (his last bottle for the night). Then he would wake up 4-6 hrs after his last bottle. Which would be anywhere between 4:30-5am.

Now we put him to bed, he’ll sleep an hr, cry we pick him up, rock him, and as soon as we put him down he starts crying. So we start the process all over again. When he’s finally down he’ll sleep till about 3 or 4 am and cry repeat the same cycle until I eventually give up and just bring him to bed with me. To which then he’s sound asleep. Idk what to do, I dont want him to get into the habit of bed sharing. PLEASE help