And don't worry too much. While it's true that this heart stuff isn't much fun at all, and can scare the pants off us, worrying doesn't help anything. It just makes us miserable. You take care of what you can, let the doctors take care of what they can, and try to roll with the punches, so to speak. Maybe you will (or won't) need a pacemaker someday, and if that's the hand you're dealt, there's nothing to be gained by worrying about it until that day comes. I'm not sure what your dad's problem is when you say severe exactly, but a pacemaker really is not that big a deal, in the grand scheme of things. Not that we want to get one, but there's many many things worse in the world than needing a pacemaker. You can lead a pretty normal (and long) life with one.
Ditto on Jerrys post.......
It would be a good idea to get a good check up at least from your primary car doctor and then only if he/she does an electrocardiogram. This could result in a need to see a specialist: a cardiologist. You can't be too safe, especially given your family history.
My guess? The stress is the cause, and you should think so to to help put your mind at rest on this one issue at least... still get it checked by a medical doctor.