Lying patient out to get me

X posted This is a long one…. I work in a retail pharmacy. A year ago, on a slow day when we only had 3 of us, an older woman who was new to the pharmacy came to pick up a prescription for Norco. The system said it was out of stock, so the prescription didn’t get filled. I told her “Oh, it looks like it didn’t go to fill because the system says it’s out of stock”. She was NOT happy. She didn’t even let me have the pharmacist look in the safe to see if the counts just didn’t get updated. I told her “We may have it, so let me check”. The pharmacist checked and we had it. Yay, we have what we need to make our customers happy. So I thought… I returned to the pick-up counter and happily told her that we did have it and that we would get it ready for her soon. This woman then started to accuse me of lying beforehand that I had to have known we had the medicine. Accusing me of not wanting to fill it because I thought she was a drug addict. That did not even cross my mind…. This is sort of how the conversation went. Lady: I don’t get it. Me: I’m sorry, I don’t know what you mean. We are getting your prescription ready. Lady: First you don’t have it and now you do? Me: Sometimes we have a product and the system says we don’t. I always double check. Lady: I’m getting bad vibes from you. Me: I don’t understand. Lady: (again with the bad vibes being very domineering) You’re being weird. You’re weird. Me:….(The pharmacist who is listening to everything steps in) Pharmacist: What’s the problem here? We have the product and we are filling it. The system did say it was out of stock. Lady: I’m getting bad vibes from her. Me: what am I doing that is giving you bad vibes? (I have bad anxiety so I’m starting to get very uncomfortable and fidgety. I was also dealing with my grandma being in hospice) Lady: she’s acting weird and giving me bad vibes(dude why do you keep saying that??) Me: Because you’re making me nervous Lady: I’m not making you nervous Me: (takes off my smock shoves it under the counter and leaves holding back tears) Later I came back and the pharmacist stood up for me and told me that the lady said that I owed her an apology. The pharmacist said “An apology for you making her cry” and the lady said I needed therapy. She called the store and the store manager talked to me and told me he’d take care of it. Then I later heard from the cashiers up front she had been upfront slamming me to everyone. That sucked but I was fine after that. Yesterday she came in and I didn’t even flinch. I was very professional with her, and kind. She was even nice too. I thought we were just being mature and acting like nothing happened. She then called the pharmacy and said I was hateful to her and threw her medicine in the bag cussing her out. I told her she couldn’t get one of her prescriptions. She said that she was told they would fire me and that before I threw my jacket down cussed her out and stormed out. She even talked to management and told them her version of events raging that she had been lied to about me being fired. She won’t rest until she gets her payback. Her lies being easily revealed won't even stop her. What do I even do? I love my job and my customers. I have a family to provide for.