Work and milk supply

Faith

I'm looking for advice from anyone who has done this. I am 7 weeks postpartum and breastfeeding my son. I'm going back to work in a couple of days, and I will be working 3-4 shifts a week. These shifts can be anywhere from 4-8 hours. I work in a fast food facility that doesn't have a break room, and there are cameras everywhere that have real people sitting in a room watching everything we do, so there is nowhere for me to pump. Just for reference, I breastfeed my son 95% of the time, sometimes we give him formula when we have to make a quick trip out, or if he is still hungry after being latched on for over a couple of hours. Has anyone returned to work part-time and still maintained a decent supply?