Son is starting preschool and Mommy is overthinking

This August not only will my son be turning 3, but he will be going to preschool! I’m absolutely terrified.😖 Me and my son are together 24/7 so I’m worried about how he’ll handle being away from me. He’s also never been around other children his age so he’s never really had to “share” with anyone so I’m also worried about that. He also doesn’t talk a lot so I’m scared that the teachers won’t understand what he needs. I’m overthinking it all, I’m scared he’ll act out, I’m just scared about the whole thing. This is going to be a BIG change for both of us.😩