Bullying

I was friends with this girl for about eight years, but looking back there were a lot of red flags. She would lie to me often and constantly insult me for no reason, calling me things like “idiot.” Her family was also rude towards me. Whenever I called her, her mum would answer the phone and speak to me aggressively, even though I had never said anything bad. Her brothers would pick on me too—one of them even called me a “lowlife” and said I had no friends.
What really hurt me was that her siblings somehow knew very personal information about me that I had only ever shared with her. That was a major warning sign. A lot of people at school warned me about her because nobody really liked her, but I ignored it.
Eventually, I cut her off. When I did, she swore at me, insulted me and my parents, and even threatened to beat me up. I’m confused because I don’t feel like I did anything wrong. All I did was distance myself from someone who was treating me badly. Am I the problem

Your the not problem nor were u in the wrong whatsoever. Maybe she's in denial and hasn't taken accountability for what she's done. When you did cut her off she muust've taken her overwhelming insecurity and fear out on you in the form of outrage. Did you explain to her as to why you were cutting her off?

I was feeling lonely and neglected by my primary school friends, so I tried to reach out to people I hadn’t spoken to in a long time such as this girl . I messaged one of my friends asking for the contact information of the girl . At the time, I realized it wasn’t the best decision — I was upset and acting out of loneliness. I asked my friend to delete the message, but she had already sent it before going to sleep.
After that, I decided I didn’t want to add that girl on social media. Her sister and she reacted very strangely, calling me a “weirdo” and questioning why I had asked for the contact in the first place. I understand that it was immature of me to ask and then change my mind, but I was in a difficult emotional space and didn’t make the best decision. Even when I explained that I never actually wanted to add her, they continued to say hurtful things, which was unfair. And obviously like that could’ve just been a sign from the universe or God to why I should never talk to her ever again. I’ve not spoken to this girl for more than five years now and I don’t wanna be her friend. I honestly find her weird and I just feel uncomfortable and unsafe around her and honestly after what she put me thru I just don’t care about her. I’ve moved on but any time she sees me on the street or any time she sees me anywhere she just starts swearing at me on the top of her lungs like oh b****, I’m gonna beat you up blah blah you know. I don’t think it’s because I cut her off. I genuinely don’t think that’s the reason but I just don’t understand why people are so weird like why do they have to react in a very weird way like if I saw her on the road, and if I was with my mates, I would never behave like that. Yeah, she hurt me, but I would never go to that extent.