New Screen Needed, Or Something Else?

Hi all

My 3 week old Samsung Galaxy S7 Edge fell off my car shelf and hit the hand brake lever.

Since then, the display has been peculiar. If I restart the phone, apart from a white line about 20% from the bottom of the screen, everything works fine, but as soon as the screensaver kicks in, or I turn off the display from the power button, and then try to get the display back again, the display is so bad I cannot use the phone.

Not sure if it requires a new screen or if it is a different problem.

Also, If its the screen, I get confused about LCDs and digitisers. What would I need to buy?

Thanks in anticipation.

Chrissy