LONG WORK DAY-HARD TO STAY ON TRACK

Hi all,
I am a nurse and find it extremely hard to stay on track with my new eating habits when I work long shifts. There are times during my 12 hour shifts when I have to give one to one continuous patient care and can't leave the pt. During those days I find it hard to eat or drink water, my quick snack includes a protein shake. Sometime I have to be at a facility where I don't have access to place my lunch bag in a fridge, so I need to take something non-parishable. With not being able to really eat all day, I go home famished and eat practically everything in site! Days I don't work or work the shifts where meal breaks are easier to take due to more nursing staff, I am able to follow my diet. Does anyone else have a similar challenge and have any suggestions for a healthy snack that doesn't need to be refrigerated?