I struggled with a lack of hunger for most of my pregnancy. The only thing I ever felt hungry for was ice cream, and I didn't need an MD to tell me I couldn't grow a baby on ice cream alone! What really helped me was getting a food check list. The one I got was part of the Bradley birth class I took, and it really helped! There were certain foods that they want you to eat every day, like leafy greens, eggs, and fruit, and you track your protein intake to make sure you are getting at least 100 grams daily. That way, when I wasn't hungry I just looked at my daily checklist and figured out what else I needed to eat that day. Even though it might not have sounded good, I felt good eating it because I knew it was helping me grow a healthy baby.
As a working mom, I know what you mean about the daily sandwiches. I enjoyed having a variety of veggie sandwhiches while peggers. My favorites were roasted peppers and cheese, roasted mushroom and cheese, and PB&J. I used almond butter instead of peanut butter because it had a little more protein per serving. I also sometimes made salmon salad sandwiches, using canned salmon, which is lower in mercury than canned tuna. We also cooked several turkeys while I was peggers, mostly to have the meat for sandwiches.
Other food staples while I was pregnant were: hummus, hard boiled eggs, whole wheat bread, beans, and salad.
Good luck with your pregnancy, birth, and mothering!