It must be hard to even attempt to use your phone being that its locked Tcgrebyn. Since phone is locked, you will have to put in Recovery Mode to restore it. Below are steps to do so.
(1) Press the power button on iPhone for a few seconds until the slide to power off switch appears.
(2) Slide the slide to power off switch right, to power off the device.
(3) Press and hold the Home button then connect the iPhone to the computer via USB cable.
(4) The Home button can be released when the Connect to iTunes screen appears on iPhone.
(5) If iTunes does not open automatically, open the iTunes application on the computer.
(6) When prompted with "iTunes has detected an iPhone in recovery mode" click OK.
(7) From iTunes, click Restore.
I hope this helps.