Sleeping on mom

My LO IS 7 weeks old. Recently, he only can fall asleep and stay asleep while on my chest or in my arms. At the first part of the night (10-11) he will fall asleep and can sleep in his beside crib but around 12-2, he wakes up and cries until I pick him up and he goes right back to sleep. But upon putting him back in the crib, he wakes up and fusses until he’s back with me.

I’ve used the warm blanket to put down before him and I also use a weighted sleep sack.

Help!!