Preschool Already?

This little man is going to be going to preschool in just 4 and a half short months.  We started the paperwork yesterday to start his transition into the school district.  They day he turns three he will be a preschooler!  (In case you're wondering, since he has a diagnosis he will start receiving services the day he turns three.)  As I was signing the paperwork yesterday giving my permission to share his information I think I had a little heart attack.  I just kept saying over and over, "Oh my, my baby, a preschooler, what the heck am I going to do?"  Seriously, I can't even think about it.  How is he old enough to be in school?  My baby?  I am having a little heart attack as I am typing this.  I know deep down this is the best for him, but I might die...