3 yr old is scared to sleep in his room

So my son is 3, almost 4, and he has always been good about sleeping in his bed, however up until recently his bed was in our room. We got a house and moved out of our apartment since we're expecting #2 and now he has his own room. Well he will not go to sleep in there. He says he's scared. So I tried laying with him til he falls asleep, putting in night lights, etc. He still cries and says he needs to sleep in mommy's room or the living room.

He would rather lay all alone entirely in the dark in the living room than be in his own bed. Idk what to do. I need some advice please! I ask him why he's scared and he doesn't have a reason. Just says he is. All advice is appreciated!