Screen Blacked out Slowly.

I dropped my phone from a certain height. Suddenly Purple/black spots were there on the screen and after a while it blacked out. The touch responds to SPen only. But everything else is working fine such as the apps, sound,etc I can receive phone calls and can call through google assistant. Someohow I was able to cast my phone screen on my pc through Smart view app. What would be the possible cause and how can i repair it ? I would appreciate any help.

PS : there are some visible notches on the screen. Might it be broken.