Storage almost full constantly, how do I make it go away?

For the past three or four days, my phone has been constantly popping up with this annoying messsge STORAGE ALMOST FULL: Manage your storage in settings, but nothing Is ever full at all! I can't take photos videos or download apps cuz my storage always stays on zero kb and it's really really making me upset, I've deleted photos and videos and re downloaded apps but i still get the same old messsge that my storage is full, what do I do?! I've tried everything and it's really making me upset to the point where I wanna break my phone