He is so new to the world, the little guy is still adjusting. Have you tried sleeping somewhere else? Some things that worked for me were going for a walk in the pram at sleep time, my girls both love sleeping in the pram, or a HAB/Close carrier or similar wrap carrier was also great, my girls both loved sleeping in that.
Sometimes a bath before sleep helps too.

And one other thing. Maybe he doesn't like the wrapping? If he sleeps 6 hours overnight in a sleeping bag, maybe try the bag during the day too? Might be worth a shot.

The first few moths are such a challenging time while you are working each other out. Hang in there, it does get easier.

I am sure you are taking wonderful care of him. The warmth and care you have for him comes across in your post, you are doing a great job. ok? x