Why is my screen black but my phone is still turning on?

Ok so i dropped my phone a few billion times and it just got a few cracks but about 2 days ago when I dropped it i picked it up and the screen was on but it wouldn't respond to my touch and it was white pink and blue. Then when I turned it on later the screen was black but like had pinkish lines that sort of followed where my cracks were and if I pushed on a specific spot if would show a part of my screen but still no response to my touch. And now its just a blank screen but the LED thing is blinking because its telling me i have a text message. HELP