If you are willing to erase your info and you really have no other choice, try a hard reset, turn off the phone and after it's completely off, press Power+Volume Up+Home until the phone turns on and keep them pressed 2 or 3 seconds after the S6 logo shows, it'll take yo to recovery mode,from then movewith volume upand down keys to "Wipe Data/Factory Reset" and choose Yes, then choose "Reboot system now" and your phone should be like it's outta the box