Even when eating was difficult due to my never-ending nausea, Mac and Cheese was one thing that I could hold down. Not sure what the magic ingredient is, but there are LOTS of pregnant people that swear by Mac and Cheese as a cure to pregnancy-induced nausea!
I practically lived off of Mac and Cheese for a couple months. I would pack some Easy Mac (don't forget the sea salt and pepper!) in my lunch, along with a box of apple juice, some veggies and dip, and a sweet treat (usually something with chocolate!), and that was my mid-day meal at work. Sometimes I'd bring some hot cocoa for a nice pick-me-up, and a nice relaxing hot beverage before my nap!
Easy Mac is great because you can cook it in a microwave with little to no effort. The single-serving size was great for me, too. You can purchase packets (provide your own bowl, and voila), or the kind that comes in a disposable cup. If you're looking for something that is a little more cost-conscious, try making a big box of Mac and Cheese, and dividing it into reusable individual-serving containers. Don't forget to slightly under-cook your pasta, you don't want it to be mush when you reheat!