Hi, does it have a raised white outline? If so, yes it's geographic tongue. I've had it for almost 20 years and freaked me out then as well.
I've had larger areas and very small areas. I make sure I keep my fingers out of my mouth, for that's what seems to trigger it. Stress, certain foods, meds...etc can also trigger it.
It's harmless, and the more you stress about it, the worse it can get.
When I get it I show my husband and he comments something like....hey, that one looks like Africa! or whatever.
Don't forget, they always show the worst on the internet...meaning the most extreme of things, but you may have that one day as well. Don't worry, please.
Check, is it outlined with white, if so, that's it for sure.
quincy