Unless you have either an old password disk or another admin account, you are stuck. We cannot give advice on bypassing passwords on this forum.
When you wrote "I have deleted myself as administrator," is it possible that you meant that your own login had admin privileges and you rmoved them? In that case, perhaps you can log into the original administrator login?
Or if you do system backups, you could restore an older backup where the account was still valid. Save any data that you have changed since that backup first.
Good luck. Worst case, you will have to use a backup utility to save all your data and then re-install.