Sad about leaving work

I'm super excited to meet my babygirl but I'm also sad about leaving my job. I'm a full time preschool teacher and I'm seriously going to miss all my kids so much. My coworkers and I have also become extremely close it's going to be so different not seeing them or talking to them everyday. Has anyone else felt this way? I know I definitely want to go back at least part time after my 18 month maternity leave but in that time so much will change. I know my baby is so much more important and I'm super anxious to meet her, I'm just so used to working now it's a big change. 😧