Coat a medium skillet with nonstick spray. Heat to medium.
Add the onion, carrot, green pepper and mushrooms. Cook for 5 minutes or until tender. Remove from heat and set aside.
In a large bowl stir together the egg whites, crushed crackers, milk, 2 tablespoons of the chili sauce, Italian seasoning, and black pepper. Add the cooked vegetables and ground beef; mix well with hands.
Firmly pat the mixture into a 7.5 x 3.5 x 2 inch loaf pan. Invert the loaf pan into a shallow baking dish.
Bake at 350°F for 30 minutes.
In a small bowl, combine remaining chili sauce, brown sugar, vinegar, and hot sauce. Spoon over meatloaf.
Bake for 15-20 minutes more, or until internal temperature reaches 160°F.