You have to unlock flashing of the firmware and then either download the Samsung specific GApps image or download the entire stock ROM and then use Odin to wipe and flash the firmware. This can be very dangerous if you do not understand what you are doing, you can completely wipe out your device using Odin, but this is also the easiest and fastest and most guaranteed method to fix it. I had the same thing happen to my galaxy tab 4, without a keyboard you cannot type what you need to type to get it fixed so you must use a Windows PC as well (Odin doesn’t support Mac as of yet) If anyone needs help tracking down your exact build numbers, finding the correct firmware, understanding how to use Odin, or anything else just contact me at broncozak@gmail.com and I will be glad to help.