It sounds to me like you probably do have some nutritional deficiencies. However, I do not believe it's because you're not eating things with all the nutrients you need (even if you weren't, unless you had an unusual diet, I don't think your symptoms would be quite so severe).
I might recommend having your stomach lining tested for damage or something. You could have celiac disease, or something similar, like a gluten intolerance, and with the proper diet, you could heal and start absorbing things properly. Improper growth and hair loss are some of the classic symptoms (although bowel issues usually get highlighted a lot more, you don't necessarily have to have them to a high degree to have gluten issues).
It might be a good idea to take some digestive enzymes, too (papaya, vegetable, etc.) They can help you digest things properly so that you don't get damaged as much by what you eat, and so that you absorb more nutrients.
How do you handle dairy products?
Do you have any skin or known bowel/digestive issues? Did you as a child?