Baby won't sleep without being held.

Anybody have tips on how to get baby to sleep without being held? 4 weeks tomorrow - would sleep alone somewhat at the hospital, but literally won't sleep in his bassinet, even if I put him down half asleep. He'll cry 5 minutes later. He won't even stay in his swing awake without getting upset lol. I know infants want to be held, but he basically can't not be held. I go back to work in 2 weeks, and need to find a way for him to lay for like an hour so my husband and I can get at least a little sleep lol.