You would need a computer to reflash the ROM since your touch screen is not working.
Download the stock ROM from
HERE
Extract the StockSprintHermanOSBigstorageRUU_dumped.nbh file out of it and place it on the root of your storage card.
Rename it to RAPHIMG.nbh
Press and hold the power and the volume down keys while you reset.
This should put your phone in bootloader mode and it should reflash the stock rom
Relocker posted
HERE