Keep in mind that when dealing with a toddler, it's important not to let eating become a power struggle or a battle of wills. Getting emotional over your toddler's refusal to eat feeds into her negativity and only makes matters worse.
First of all, just because she doesn't like the supper you prepared does not mean you are a bad cook or that she will not really love your meals in a year or two. Her refusal is not about you.
Second, keep in mind the purpose of food. Eating is the way we fuel our bodies. Good nutrition keeps us healthy and growing strong. A toddler needs between 1,000 and 1,400 calories a day, depending upon the child's age and activity levels. Even these numbers, however, can vary from child to child. As in so many other areas of development, there is no rigid standard on what a child of a particular age needs. Children are individuals and have their own levels of metabolism and requirements.
A third thing to think about is that you, as the parent, are in charge of which foods to offer your child. The child doesn't have an inner desire for candy or junk food. The child only knows the foods he or she has been exposed to. You are the one who determines which foods to present to the child. The child, on the other hand, is in charge of how much to actually eat. If you offer a variety of foods -- in small portions -- and vary those offerings, your child will eventually get what he needs.
Don't worry if there are days when your child doesn't eat as much as you think he needs. He may make up for it the next day. Evaluate what he eats over the course of a week rather than day by day. You will get a more accurate picture of his nutritional input in that way.