Pump breaks

I’m allowed to have two pump breaks 10-15 minutes. During my 5 hour workday. But I’m not allowed to have food or take a lunch. Only water. I have no access to a fridge or microwave and so can’t really sneak anything else. What do I do? My supply is dwindling. I eat a granola bar during my pump breaks. That’s it though. This is what I got after pumping 15 minutes.