My son is almost 6 months old he got hit in the head the other day by his cousin with a toy. Since…

My son is almost 6 months old he got hit in the head the other day by his cousin with a toy. Since then he has been having trouble sleeping he wakes up screaming and crying on and off all night long. Idk what to do to make him sleep better or help him with his fear of going to sleep. Can any mommy's give me any ideas to help him out. I feel so bad