I dropped my phone and my screen is mulitcolored and wont respond

Ok to this happened a week ago, i dropped my phone flat on the concrete and the screen went first. Of course i wasnt wearing a case so the screen cracked. Its not a horrible crack but its not small. So, a week later, after school i went to go turn on my phone and when it turned on my screen was all fuzzy and different colors. Everytime i touch the screen tol it does not respond. when you touch the screen, thr colors change and sometimes gets worse or better. I have an iphone 5 with ios 8 and im supposed to get the iphone 6, but the phone store does not accept broken phones. Does any one know if i can fix it myself without bying a new back light and stuff? If not, ill just have to go and get it fixed. But if you know whats wrong please help Thanks!