ok gawin natin kung marunong kang magbukas ng phone mo (Do it at your own risk)
-remove screws of your phone
-open and look for some ribbon connectors and carefully remove the ribbon connector of your touchscreen to their socket (you must know how to open the lock in the socket)
-Turn on your phone without the connection of your touchscreen
-hard reset your phone and turn it off
-then connect it and screw it back
-and turn on your phone and test if the touch is working
Note: IF this is not working you better go to a Cellphone technician to replace your touchscreen