IPhone XS screen turned bright green with harsh, neon burn lines

Out of nowhere yesterday while I was using my iPhone XS, the screen turned bright green with three burn lines: one long, burning-bright white strip down the left side of the screen, and two green ones on top. (I didn’t drop the phone, and I didn’t spill anything on it.) If I lower the brightnesss completely, I can manage to read the text on-screen, but it hurts my eyes to look at the screen for more than 30 seconds, and I’m worried about the damage.

I’ve tried 1) turning the phone off normally, 1) turning it off by holding the volume and side buttons, leaving the phone off for 30 minutes, 3) changing the display settings to lower and raise the brightness, 4) turning True Tone on and off, 5) updating to the latest iOS, 6) performing a full reset of the phone.

None of these have fixed the issue, and I’m currently traveling abroad for two and a half weeks in a country without an apple store (Portugal). What should I do?