My Landlord Wants To Sue Me Because I Sent A Complaint To The City Hall For Operating Without A Permit

So I was renting this studio type apartment for like 7 months and I noticed that the landlords keep on meddling with my own personal life. I have an ex boyfriend and he keeps on trying to get me back to the point where it scares me because he’s always waiting for me in front of my apartment. My ex eventually spoke to the landlord to help him get me back and he agreed, he even gave him a spare key to my apartment without me knowing. That time I was already dating someone else and the landlord still keeps on trying to help my ex (he accepts gifts that my ex wants me to receive) even if I already told him to stop meddling and my personal issues are not his business. He doesn’t know any boundaries. So long story short, I was triggered and I filed an anonymous complaint to the city hall for them because of operating without a business permit. They found out eventually that it was me because of a photo of a screenshot of our conversation (the photo was attached to the inspection notice that they received). I eventually moved out because they told me to tho I was planning to move out too) However, after moving out, they kept on harassing me through chats. They even got some of my personal videos from their cctv camera and sent them to the people I worked with, to my parents, and to my ex. They’ve been going to my workplace and telling people stories about me. It stressed me out. Now, I heard from one of my workmates that they want to sue me for filing a complaint. They keep on insisting that I paid someone to inspect their business. The complaint was sent anonymous and no one knew about it in my workplace.

What do you think should I do? Can I file a case against them for harassment?