You can raise the garage floor and stop at the door, depending on how much higher is the driveway, but the typical garage slab can be raised 1 1/2" ... Something like this to give you an idea

"How can I easily fix this?"

No easy fix. Either raise the garage floor like above or have the driveway removed and the entire area regraded. Neither fix will be cheap.

Thanks guys! That's what I feared.

You could try a trough drain just outside, and the entire width of, the garage door, providing you can duct it downhill.