How to fix my broken iPhone 4 screen?

I have an iPhone 4, and I don't really know what happened to it, but the screen isn't working properly. I dropped it, but it was fine until a few minutes later, when the screen turned yellowish/greenish and then the phone went black. I can still hear rings from the phone as well as vibrations. When I press the power button, I can kind of see the screen light up a bit, and sometimes the screen turns grey. If I swipe and press where the numbers are for my combinations, I can hear my phone unlock. I can even take pictures, but I can't see anything on the screen. This happened maybe 6 - 7 hours ago. I tried connecting it to my computer, but I don't know how to restore it on iTunes. It also says that the DCIM folder is empty, even when I unlocked my phone. I have already tried turning it off, even the one where you hold the power and the home button at the same time. Nothing worked. Please please help! I really need my phone, and getting a new one is not even in the question… Is there any way I can fix this?

You can get your phone repaired at a local phone repair shop. If it's just the screen, it'll cost you about $100.

There's nothing you can do to fix it yourself.

I wouldn't do it by yourself, you could completely break your phone. Take it to a phone shop they'll sort it out.