Deleting playlists on Iphone is deleting corresponding playlist on Itunes--and can't get back!

For the longest time, I couldn't figure out why my recently added Itunes playlists were disappearing. Would do everything suggested to recover but they were just gone.

Finally realized today, everytime I delete a playlist on my Iphone to make more room, then sync with Itunes on the PC at a later time--that same playlist also is deleted. I'm assuming that the "sync" function is telling Itunes to also delete the same playlist in Itunes.

What the heck?? This never used to happen and I'm at a loss on how to prevent this without overloading my Iphone with playlists. And I've tried all methods to recover them and they are evidently not recoverable.

The music is still in my library on Itunes but the playlist is gone. WHY??????