My phone has colored lines on it and is not usable, help!

My screen has a bunch of colored lines after I dropped it, I could still see my messages kinds through it but the touch screen didn't work. It's been a while and now the back ground is just white and colored lines, I can charge it and it will make a sound when it's plugged in and when It was still connected u could hear it ring and vibrate. I'm wondering if do I just need a new screen or to fix the whole phone it's self? Is the damage internal or just a screen issue? Thanks!