I wonder if I actually have epilepsy....

So I was diagnosed with epilepsy based off of the only seizure I've ever had because of the fact that I had a bad head injury about 10 years ago. But the night (well technically morning, 3 am) that I had the seizure, during the day I worked 12 hours and had 2 big Java monster energy drinks and I was only working on about 5 hours of sleep to begin with and was awake for about 22 hours at the time the seizure occurred. The doctor was quick to assume that it must be epilepsy because of the head injury many years prior. I was put on Dilantin after the injury as a precautionary measure and I requested to be taken off of it about a year later because it made me feel like sh** and I didn't have a seizure it anything until many years later. I had no issues with coffee or lack of sleep it anything until that night. So I still wonder if I am actually epileptic or it's just based on assumptions by the neurologists.