SO HERE WHAT U NEED TO DO:-
flash the rom via odin (http://www.sammobile.com/firmwares/3/?download=30198)
if u get a freeze ing the activation just quickly finish the activation if not the WIPE DATA & CACHE and then ACTIVATE.
and dont use ur old or previous google account on ur phone it will bring the backup and the backup will bring the bugs and all te nonsence back to your phone so make a new GOOGLE ID and SAMSUNG ID for app downloading..
and what ever u do dont update your phone it will take you back to your previous firmware and u will face your problems again. SO do this to prevent it from updating wait till the real fix comes out..... got settings - General - Application manager - ALL - scroll down and find 2xSoftware Updates and FORCE STOP them both and when you connect to the wifi it wont update
Hope that it helps you out as it helped me