Some of this is just natural. One of the things you’ll find is that pits are very, shall we say, clingy. They quickly bond with the people or person who cares for them. He may be a little down at first, if he has troubles at night try a warm water bottle wrapped in something fuzzy. The warmth and something to cuddle up with will comfort him. I don’t suggest you do what we did and let him get in the habit of sleeping on the bed with you. They grow up fast and become TERRIBLE bed hogs! Kaos spent the night last night on his back, all fours in the air, squashed between my husband and I, for all the world like a little kid after a bad dream. At any rate, just love on him and let him adjust. He will soon be following you EVERYWHERE and crying if he can’t. You don’t need to worry about him missing his mother and siblings for too long, he will love you wholeheartedly in a matter of weeks. It’s very characteristic of the breed, part of the reason we all love them so much.