Seizures can actually occur at any age and can be caused by many different reasons including genetic or hereditary epilepsy, tumor, infection, stroke, metabolic (like electrolyte abnormalities), head trauma, and unknown causes among many others. There is even a relationship with migraine headaches. New onset seizures in a 19 year old should prompt a full neurological exam, EEG with light stimulation and hyperventilation, and an MRI of the brain as well as more routine laboratory testing. There is a hereditary epilepsy called juvenile myoclonic epilepsy that typically presents in your age group. The MRI is normal, but there are classic changes on EEG in reaction to light/photostimulation. Patients usually complain of little jerks or twitches in the morning on wakening or brushing their teeth. Then they have a generalized seizure (grandmal) at about age 16-19 when they go off to college. Can be precipitated by alcohol and sleep deprivation. Just a thought. Fortunately there are a lot of medication options for this type of seizure syndrom (syndrome) as well as generalized seizures that aren't a part of the syndrome.
You need a full workup. Get a second opinion at a major academic center nearby for further evaluation and treatment options. Good luck.
If you're feeling all alone and want to share your experience with others or read about theirs, this is a good site:
http://neuro-mancer.mgh.harvard.edu/cgi-bin/forumdisplay.cgi?action=topics&forum=Epilepsy&number=33
That sounds like a commercial. LOL But the site has been a great help to me and so many others.
Good luck
Good Luck!