What does your doctor say? I think with your cerebral palsy and lower stature you might have problems that could affect why you don't wish to eat/feel hungry?

Are there foods you enjoy more/less than others? I would try a naturally high fiber diet to make sure you do not suffer from constipation (I eat popcorn almost every day, it's a whole grain and high in fiber), constipation can often make one feel they have less energy. If there are fruits and vegetables you enjoy, I would certainly try to increase them; I aim for 5 fruits and/or vegetables a day and usually have no problem since I love fruit and veggies. Eating well makes it so I don't have to eat as much and crowds out less nutritious foods so I sleep and feel better.