iPhone 8 Plus. Screen easily scratching and cracking when playing any sound

I’ve had my iphone 8 plus a couper of month now. In the beginning I noticed small scratches on the screen from basically nothing at all. I’ve dropped my phone maybe one time, but nothing to bad. But now after a couple of month my screen is filled with smal but long scratches? I don’t put my phone in my bag with other things. I always carry it in my hand or in my pocket. The screen seems to be very fragile?

My speakers are also cracking every time I’m playing music or watching YouTube. What is going on?