Custom Ringtones and the new iTunes

I'd really like to be able to update my ringtones, but with the disappearance of GarageBand from my app store, I can't use that to create them, nor does editing the files and trying to drag them into the "tones" folder on my iPhone when available to select in iTunes (when it's connected to sync) work. I have tones that I previously created. I just can't add anything to that "Tones" folder or access them as a tone.

I understand there is a desire to sell ringtones, but if the ringtones are not available to sell (or are my own voice or my child's) then how can one make new tones available for use as text tones? This function should be available. I have a 5s and I'm especially concerned if I end up trying to upgrade my phone that I'll even lose the old ones with my children's younger voices. How can I add and update my ringtones list? The discussions listed on this discussions.apple.com website seem outdated because they only list iTunes 12.7 and later. We're on iTunes 12.10. I know there's a line in there about deleting old ones before updating the new, but will that really work or will doing so lock me out of using my custom ringtones forever? I'm very afraid to try that method. Is there a way to try that, but use a backup to restore them if something goes wrong or if I delete, are they gone for good?