i updated 3Gs iphone to OS 6.0.1....only apple logo and loading display now shows..

hi,

I have a 3GS iphone, updated 6.0.1 OS now phone only displays apple logo and loading bar. at first showed plug sign and i tunes display..tried to restore but wouldn't allow..tried removing sim card and turning off and on..nothing has worked..now only apple symbol and loading display show...shuts off and restarts automatically..driving me crazy!!