Hi. I searched and surprisingly found nothing related to my issue. All of a sudden, all video, including menus/settings menu, etc stretch well beyond the sides of my screen. Nothing changed in my home environment that I am aware of. I did try rebooting the fire stick, and obviously I want to avoid resetting to factory settings if I can avoid it. Any help is appreciated.
So, apparently there is a secret 'zoom' function via the Fire TV Remote that I was (and am still not) aware of. Not sure how I fixed the problem exactly, but it's back to normal. Wish I knew how. Thanks everyone!