"Unintentional weight loss" does not compute.
You've gotten a taste (pun intended) of life without fast food and all the yuckiness we busy people tend to live and kill ourselves on. Try to make some basic food components on the weekend that can be thrown into a salad, sandwich, tupperware whatever to take with you.
I'm a huge fan of soup for lunch at work. It's hot and filling and gives me a warm fuzzy feeling even if it's only 60 calories a cup or something. I also keep laughing cow cheese, hummus and Wasa Light crackers for snacks. Sometimes I'm not quite hungry but I feel the
need to eat. One of those crackers and a cheese wedge for maybe 70 calories can satisfy that need without running to the vending machine.
After avoiding fast food, it may make you sick. Remember that when you're eyeballing the burger and fries. My husband isn't actively trying to be healthy but he gets it by proxy. He had fast food a week or two ago after a few weeks without and was literally sick the whole next day and was completely lethargic.