When ever I travel I take a stash of foods that I've prepared, seperated, frozen into servings if possible so I can grab for something good when I'm to tired or can't find another option, they include:
crispy nuts (almonds, walnuts, pecans, cashews) soaked and dried, I take several full zip locks of each kind. keep in refrigerator
unsweetened dry coconut, you can get this in groceries as well while traveling
dried fruit rolls which are a mix of fruit, coconut milk, nuts: portioned and individual servings (I do these in bulk once a month for snacks so they are ready to go)
you can purchase fruits in any grocery fresh, add yogurt. If you eat raw veggies you can eat carrots, celery with cheese
I make GAPS pancakes in a variety of flavor, each serving is basically 1 egg, .75oz of any nut, 1/2 small banana, puree, cook. I usually make 4 servings at once and freeze. Add in blueberries once its pureed or change out bananas to pumkin. These are great warm or cold for a meal or snack if needed. Balanced fat, protein and carbs about 300 calories per serving
If you concoct any type of 'protein' bar or chococlate snack full of nuts, coconut, you can do individual servings.
precooked crisp bacon in a baggie.
I tend to bring more than I need, but that comes from being stuck not finding food when I want it.
Grilled anything is usually pretty good, with steamed veggies at most restaurants.
Breakfast meals for lunch or dinner if possible are always good, eggs, bacon, veggies, butter.
These opts can keep me happy for only about 4 days, after that I want home cooked meals. Hopefully this will help get you through the rough patches!!