you definitely need more food mama!! I'm having the same issue, and I eat way more than you!! I keep away from dairy, soy and gluten, so I'll give you an example of what I eat:
Breakfast: 2-3 eggs with 2 pieces of gluten free toast with jelly (cooked in a hefty amount of earth balance soy and dairy free butter or oil) or soaked oat meal. sometimes i have oatmeal with a fried egg on it - yum! and i have a cup of coffee, orange juice, and a granola bar or power square (a yummy treat made locally with nuts and dried fruits) if i'm still hungry.
Snack: peanut butter and jelly sandwich, or fruit
Lunch: anything from two sandwiches to left overs from the night before
Snack: hummus, guacamole, sweet potato chips, fruit, salad, granola bar, or another peanut butter and jelly sandwich....sometimes I have second lunch
Dinner: varies widely, but some ideas, crock pot lentil soup, pot roast, rice and beans with veggies, beef stew, roasted eggplant, pasta with mung bean noodles, pasta in general with meat sauce, pork chops with saukraut and potatoes, roasted chicken (make chicken salad and chicken stock with the leftovers), meat loaf, pasta salad, sweedish meatballs, steamed fish with red sauce, veggie and bean soups....pretty much whatever I make, I make huge portions so that I eat a lot at night and have left overs that I can either reheat the next day or use in another dish.
While I was figuring out what I could eat/how to cook, I also would make two protein shakes per day. I always use a lot of oil/butter just to take the calories up a notch. I found dairy/soy/gluten free ice cream ("so delicious" with coconut milk) and I indulge in that at night. Making a chocolate protein shake with peanut butter and a banana was an awesome way to end the day.
Basically, I try to eat if I'm hungry, so I want to always have food on hand. It's actually hard to eat all of that food every day, but I NEED it to get by. I seemed to have bottomed out at 5'9 and 120 lbs, and even with all of this, I still haven't managed to put ON any more weight....but I am almost exclusively nursing my almost 30 lb 11 month old :) Good luck!!