Your baby will be fine. Try to relax and think positive thoughts! It's an empty feeling when they're not home esp. overnight. You wonder what goes thru their minds but believe me he'll be great. I was so worried the night before I left Ralphie for stone surgery/neutering/teeth cleaning and I was told he might need to stay overnight. I brought him in at 8am and by 3pm, the vet called and asked if I'd like to take Ralphie home. I was thrilled to go get him. He was not active the first 2 days because of the stitches so I didn't have to worry about him running around. He had alot done to him so he was just not himself but by Day 3, he was playful Ralphie again!
Good luck from Ralphie and me!