that's not too long at all and 18hr is pretty good. 18/6 has been the sweet spot for me so far.
It varies quite a bit but first meal is usually protein shake with berries, pb or pb2, chia seeds, fage yogurt, oats maybe, milk. top it off with sugar free cool whip or whip cream.
second meal usually different kinds of meat over lettuce with mozzarella. throw some pasta sauce over that. if I feel like it some kind of carb, usually sweet potato with some pb, cool whip, cinnamon. in between that usually a quest bar, nuts, or something.