If you can't enter your Google information in order to reset the phone through your mail account, the only thing that you can do is to perform a factory reset of your device. This can be done by turning your phone OFF first. After you did this, press and hold down the Volume Up, Volume Down and the Power button until you see two lines of options on the device's screen. From there, use the Volume Up and Volume Down buttons to navigate and chose Recovery menu > Wipe data / factory reset by pressing the square button from the bottom left side of the phone. You should be able to use your phone again.
