C.B.
Get the book "The Kissing Hand". It's a children's story about a baby raccoon who was afraid to leave his mom and go to school.
I bought it and after reading it, my oldest GD had to be hospitalized in a behavioral health hospital. She was 11 and this was the FIRST time she was away from family. She was sooooo scared. Before I left the hospital the first night, I told her the story, kissed her hand and left. The next day, the nurses told me that they had noticed her rubbing her hand on her cheek and then smiling. She had done well all day! It was the story.
Good luck to your little guy. I think the book will really help him.