What happened to my screen? Please, please help.

Hey everyone. I just noticed these spots on my 3DS LL’s screen, and I’m panicking. I just bought this, and it was super expensive due to its condition. It looks like some kind of damage to me, and I don’t know what to do. To be clear, I’m in a totally dark room so this isn’t a reflection. Does anyone know what this is? Is it damage? And if so, do I need to worry about it worsening? If the screen needs replacing, I can’t do it myself. Are there any reliable services online that offer this? I’m genuinely just panicking. I’ve had so many issues with electronics lately…