Going back to work

How is anyone that has to go back to work handling it? Some days I'm excited to get back into routine and other days I freak out thinking about it! I cry and get sad and depressed 
I'm staring a brand new job causing me to go back a week and a half earlier than I had expected .... I'm scared excited nervous but get so freaked out when I actually think about leaving her. I thought about going back part time but this job I got is too great of pay and opportunity to not take it any advice thoughts comments would greatly be appreciated 😊