At this point, you are at a state where you believe that the passcode is 4 digits and the iPhone believes that it is an Alphanumeric code. It is safe to state that you will not be able guess this passcode and will eventually end up disabling the iPhone after trying a certain set number of trial attempts.
You will need to reset the passcode on the iPhone. You will need a computer to complete this task. You can reset your passcode by following the instructions in this article by Apple ➔ How to reset your passcode on a disabled iPhone. All your data on your iPhone will be wiped clean in the process.
If you have a backup created then you can ➔ Restore Your iPhone from that backup file. If you do not have a backup file created then you will lose all your data on the iPhone.
If Photos, Messages and Contacts are synced to iCloud then you will be able to retrieve them after setting up iCloud on your iPhone after you reset the passcode and sign into iCloud.
Axel F.