I am your age, Tricia3909. I don't drive truck (though I have a sis and brother-in-law that do, and she has a hard time getting activity in, also), but for the past few months, I was taking online college courses and sat for hours per day at my laptop or reading text books. I've gained 30 pounds in the last couple of years, as a result.
It is soooo hard to lose.
Just some suggestions for your mini fridge: light yogurt (if you add a spoonful of plain oat bran, it makes it slightly chewy, like granola, (it's actually really good!) and REALLY fills you up, not to mention adds in fiber), laughing cow cheese, carrots and/or celery with dip made from lt or fat free sour cream and Hidden Valley Ranch dip mix, sugar free, fat free pudding cups for a sweet tooth, maybe make up some low fat ham or turkey sandwiches on light bread with whatever you like on them before you leave?, hard boiled eggs, instant oatmeal or cream of wheat packets (get hot water at the convenience store).
Just some ideas. I know I would have MUCH more to lose than I currently do, if I ate nothing but fast food or convenience store foods all week.
Good luck to you!