Toddler and mommy sleep routine needs adviceeee

So

My son used to sleep so well, i would literally put him into his crib wide awake and he would fall asleep on his own. A lot has changed since then. Once he turned 2 he became I guess more aware of his surroundings and started becoming scared at night. He no longer wanted to sleep in his crib. Would jump out at night and come into my room crying so I would walk him back to his crib and he would cry cry. So I decided to sleep with him in his room (full size bed).

Then we decided let’s just make the switch. Bought a side board so he wouldn’t fell off bed but every single night, 1230, 2, 4 whatever time he would wake up and see I am not in bed next to him he’d make his way back to my room. Whine or cry; grab my hand and walk me back to his room . But when that happened it would take me a while to fall back asleep!! So I decided to just sleep in his room with him to prevent that. I needed my sleep too!.

But now I’m pregnant and expecting in November so we need to implement some serous changes.

Can I please get some pointers from you mommy’s that have perhaps been they this? How do I get him to sleep on his own?!

Thank you!!