Dilemma: trying to eat clean and working doubles

Not sure if I've made it public knowledge, really, but I started a new job about three weeks ago as a server at a restaurant. It may not be what I'm ultimately going to do for the rest of my life, but I really love my job. I like it because it's fast-paced, I'm always moving, and I get to interact with a wide variety of people. It's fun, interesting, and everything about the food and the business is fascinating.

Working strange hours makes a few things difficult; I've already accepted that on days that I work doubles, I probably won't get to work out as much as I'd like (which is fine, since my job is a lot of moving and carrying plates), but figuring out how to eat has definitely been the most difficult part.

My nutritionist has told me that I need to be eating every 2-3 hours, every time being a combination of carbs and protein. With doubles, I'm often working 4-6 hours at a time, with a 1-2 hour break in between. I'm struggling to figure out ways to carry a lot of lean protein -- egg whites certainly aren't as portable as I need them to be, and there's nowhere for me to keep Greek yogurt cold.

It's a dilemma.

Luckily, I get to meet with Erika again on Tuesday, and I'm hoping she'll have some good portable meal ideas. I'm definitely planning on bringing skim milk with me to work to be able to drink while I'm working, since it's a pretty decent combination of carbs/protein to serve as a small meal while I'm working longer shifts.

Anyone have good ideas for portable clean eating meals that I could take with me?