Found the fix!!! (Yes, i am user96758)
After 3 hours of investigation, internet and uncle Google wasn't helpfull at all.
The problem was that field was created via Drupal UI in Content Type -> Manage fields.
And it was deleted programatically by using UPDATE (code example below), not by using UI.
$update_manager = Drupal::service('entity.definition_update_manager');
$definition = $update_manager->getFieldStorageDefinition('field_name', 'entity_id');
return t('Entity: field was uninstalled');
I have installed module named "Devel", which is pretty good damn module and every developer should have it.
I was finding anything that contains name of my problematic field.
Thanks to Devel module i was able to find config of this field.
Usually you can see all configs at url (your_site)/devel/config
Well, i was desperate, so the last chance was to delete the config i found.
Usually the fields are named: field.field.(entity).(entity).(field_name)
I removed the config with this code below
Then i CLEARED CACHE and IT WORKS AGAIN!