iPhone 6 touch screen problem
I'm having trouble interacting with my iphone 6 through the screen. I can use all the functions that involve my side volume and lock buttons. My home screen button works just fine as well. To reply to text messages or open an application though, I maybe have to hit the same letter or icon 20 times before it actually selects what i want it to and once it does, I have to touch the next letter or action the same amount of times. Some times I'll unlock my phone and can interact with it for maybe 15-20 seconds before my phone stops responding to my finger on the screen but most of the time it doesn't respond at all. Any suggestions?
iPhone 6, iOS 8.4