sending my baby to school

Im a SAHM of two girls. Im having a really hard time with the thought of sending my oldest to preschool at the end of this month. Just because ive been with her most days all day. And it feels like this is the start of her not needing me anymore. (I know dramatic but it’s literally breaking my heart) its 5 days a week 2.5 hours a day. Idk why im having such a hard time. I know shes ready and she loves kids. I dont want to hold her back because of me. And I know if I didn’t she would be so bored at home all day. How do I help myself get through this. Im literally bawling my eyes out right now. What did you do to get through this?!? Im just dwelling on it its killing me 😩😭