It's PKU for short, the actual disease name is Phenylketonuria, so if you have it, you are called a phenlyketonuric.
It's tested for (but not always caught/treated) in newborn babies. If you had it, chances are you'd know it.
Phenylalanine & Aspartame are 2 different chemicals. Phenylalanine is safe to those who dont have PKU, but Aspartame can still be harmful, but typically only in large dosages.
Babyfaced, go to your doc and tell him whats up so he can run some tests...SERIOUSLY. Tell him about aspartame related headaches.
Sucralose (brand name: Splenda) is already a better art. sweetener than aspartame, just not as well accepted yet. Expect to see more and more products contain sucralose. Diet V8 splash and other drinks have it I believe, and you can buy it by the box.