The child was skipping by me so I tripped him.
Do you think it was a good idea to trip him?
No, I did that because I was tired and angry.
Tripping someone, especially a child, is a dangerous thing to do. They can seriously injure themselves when they fall. It will also make people dislike you if they see you do it since it makes you come off as extremely mean.
He'll be fine. I do feel bad though.
At least you feel bad about it, so it should be a lesson not to do it again.