I am sorry to hear that your phone is having such problem. Instead of reset, I suggest you re-flash the firmware from samsung care.
About the Secure Folder data restore, your normal backup will not include Secure Folder data. You have to take backup of secure folder content explicitly from inside secure folder > settings > backup and restore. If you have not done so, your secure folder data was not backed-up and you have nothing to restore. If you have that backup, just sign in to samsung account inside Secure Folder and restore from there.