Austine, just a few things. Not sure how long ago your phone got wet. It is possible that you have some corrosion building up. The best to do is to follow this guide. It is for a 3G but essentially the same. Make sure that all your connectors and connections are clean and properly placed. Pay particular attention to connector #2 that is the one for the touch screen. Check the cable and clean it of as well. After a proper cleaning, reassemble and re-evaluate the damage. If it still remains unresponsive, replace the digitizer. I prefer to replace the whole assembly since it is easier and quicker. the guide for that is here. The assembly is available at places like this or for really good quality and great support you can get it right here.