Since you are prgenant you should be eating about 300 more calories per day. These extra calories are used by your baby to grow and shouldn't add excess weight to you. You want your small meals to be healthy. Try whole wheat english muffin (toasted) with peanut butter and sliced banana and sprinkle wheat germ on top.
Idealy you should have the following per day:
5-10 servings of fruit/veggie (1/2 cup for most, 1cup lettuce, 1/4dried fruits)
3 servings of protein (3oz meat, 2tbs peanut butter, 1/2C beans, 1 large egg, 1/2 cottage cheese)
3 servings dairy (8oz milk/yogurt, 1oz cheese)
6-11 servings of grain (1 slice bread, 1/2 pasta/rice/cereal)
8 or more cups of water - not enough water can lead to bladder infection
Since you are not feeling well eat what you can. At this point you are more at risk for weight loss than excessive weight gain.
You seem to have some very specific questions about diet/nutrition during pregancy. It maybe helpful for you to meet with a nutritionist or dietitian. Ask your doctor for a referal.