Screen not working, PLEASE HELP

Hello, My screen no longer works. I did not drop my phone or anything that would have physically done damage to it. I can see people are calling me and I see text alerts and such but the phone will not allow me to open as the touch function is not recognized any longer. I tried updating with iTunes but that did not help. PLEASE HELP!! I am hope with two kids and have no way of making a call for an emergency.