I have a question for working Momma's! I've been back at work for almost 5 weeks now and leaving my…

I have a question for working Momma's! I've been back at work for almost 5 weeks now and leaving my son isn't getting any easier. I only work part time, 5 hrs a day, but every time I go to leave him I get so sad and depressed! It hasn't gotten any easier, almost feels like it's getting worse! Any tips on how to make it easier? I know it's harder on me than him. He does fine with daddy when I'm gone, it's just I can't control my emotions when we have to say goodbye!