Stuck in "This accessory may not be supported." Can't restart.

Did "everything" include cleaning the charging port? Under a strong light, using a magnifier if you have one, inspect the charging port for pocket lint or other debris. Using a non-conductive tool such as a toothpick, carefully remove anything lodged there.

And no, you haven't been hacked.

Hi RachaelMaci,

No, your iPhone has not been hacked. Since you cannot restart your iPhone the typical way, you'll need to force restart it to remove the "This accessory may not be supported." pop-up. Here's an Apple Support article on how to do this: Force restart iPhone - Apple Support

Hope this helps.

-Dallen