I dropped and broke my Lumia 640. What should I purchase to get it fixed?

When I run my hand over the screen itself, there is no crack or scratch. But the display looks cracked, I believe I need to buy a LCD display but I don't want to spend $30 on the wrong thing. If anyone has had this problem/incident please help me out and tell me what I should get to fix it. (I don't want to buy a new phone)

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