Advice on son starting Pre-K.

My son starts pre k soon and he is extremely shy and clingy. He’s never really been without his parents or grandma. He’s always gets babysat by grandma with no other kids around. I am scared to death to leave him cause I know he will scream and cry when I leave cause it’s a new and scary situation for him. It’s only 3 hours and I know if we give him the chance he will love it but I know the first week or so will be hard cause he doesn’t like change. Has anyone else went through this? I’m

Scared just thinking about it