Yes, it ended when I left. Funny thing this person was hired after me and my bosses had always been my friends before that. I was their junior they were teaching…small firm, we were like a family. Then they hired this other person who managed to got more credibility than me in cases similar to yours (that I was nasty at other co-workers etc). Finally I left and gave up trying to figure out what was happening, why they thought this person is more honest than me at the same time as they were saying cheesy stuff that I am like a daughter to her… It was dumb and absurd now that I think about it.
Leaving was a great decision and the only regret I have is believing all their cheesy stuff and actually trying to explain myself as if their opinion mattered.
If this job is vital for you and you need it, say you are sorry, let them think whatever they want and end all self-justifications. They won’t be convinced you and you will only get to feel worse. It may impact your health and sanity and then you will be in a vicious circle. Keep what you have - that is your health and sanity - and put your job in the background.
Actually if I were you I would give this slanderer satisfaction and apologize and get along with my business. It really doesn’t matter … God knows the truth no matter what and He’s your only judge in the end.