please give me advice

I'm a new mommy, single mommy at that. My baby was born 3 months early so she's in NICU. I need help with breast pumping. They told me to pump every 3 hours but I work 2 jobs. 1st job 10:30am-3pm 2nd job 3:45pm-12:45am. I don't have time to pump milk every 3 hours. Now I noticed when I do pump I don't even get a whole bottle (I pump for 15 minutes) I really need these jobs but the fact that my milk is slowing down is scaring me. Like is the milk going away? What should I do? She 27days & 2lbs 15oz & they're going up on her feeding. Please help.