Hi,
Do you like to cook at all? Or you just dont have time? If the answer is yes you like to cook. You could try taking one day a week and cooking for the whole week. Breakfast lunch and din din.
If you must eat out you could always get a salad of some sort with chicken on it. Like a ceaser salad but put Ranch on it. I heard ceaser has the most carbs. Or you could get a sandwich of some sorts and just take off the bread. (I find it hard to waste bread like that.)
Now about the coke. I hated diet pops they were always too sweet. Do you like vanilla coke? If so they have a diet Vanilla Coke It's great. I dont have one everyday though maybe once in a week or so. In fact i havent had one in about a month.
Hope this helps! If not i am sure there will be someone along with more suggestions.
Toodles,