how do I prepare myself for preschool

Im a wreck right now. My daughter is turning 3 in August. Do I send her to preschool?? I know she will love it and benefit from it and I do need a break (I have other kids). But shes my baby. Im a mess how do I prepare for this or help myself get over it 😭😭😭. Every time I think about it I want to cry and idk what to do? Btw im a SAHM