Pumping/BF and going back to work. HELP

I have 4 weeks till i have to go back to work and havent started pumping yet. I am freaking out about how to get a schedule in order and when, how long, how much in order to start a stash for when I start work and how to keep a good stash. Theres so much confusing info online and I feel like I'm going crazy and like I'm going to fail:( Can anyone give me advice as I am desperate.