No one in my family has ever been diagnosed with hemochromatosis or had any of the symptoms; how could I possibly have this disease?

Recessive genetics. Hereditary hemochromatosis is a recessive genetic disease - you have to inherit two mutations, one in each of your two hfe genes, to develop this condition. Your parents would be carriers but completely unaffected. What's more, only 10-15% of folks with two mutations ever get sick. The american hemochromatosis society (http://www.Americanhs.Org/) has more information.
Parents are carriers. In the usual situation, both your parents are carriers and you got one dose for each. This is basic biology and you probably learned about Mendel's laws in school. If not, please get yourself a good update so you can understand 21st century biology. People who have hemochromatosis but remain in denial die miserably. Get a 2nd opinion if you have doubts.
Hemochromatosis. Are you sure you have the disease? Have you researched all the options and truly been diagnosed. If so, you have to understand that many people are carriers of certain genes without actually having the disease. The genes they pass on can then become active if they have a child with another carrier for that genetic disease. Sadly, disease has to start somewhere...Maybe u r the 1st in ur family.