Why is my screen staying black on my Samsung s6active but has sound?

I did drop my phone. I've never had this happen on old phone when dropped before. But my Samsung galaxy s6 active hit the floor ( in its case) an when I picked it up the screen was black an would not do anything. But yet I can still here the phone ring, messages an notifications sounds. I just got this phone too an love it. What is the matter with it? an can I fix it? An is it going to be expensive an worth it? Thank you