Search Results: alone places with girlfriend

My ex friend lost a 'split/blunt' (whatever you want to call it), she then self harmed. I'm an ex self harmer and I've had to have 4 tattoos to cover up my scars, so you can imagine how insulting it was to me. She claims she has a 'cannabis problem' but I have a brother who is addicted to cannabis and she nowhere near compares to him. You can imagine how much is angers me.
We had a night out once and she completely ruined the night for us, this was one of many times she has annoyed me.
The final straw for me: We was in a different city and she dragged me along and I made it clear I DID NOT want to go. She basically left me alone because she was with another friend so my girlfriend came and met me so I wasn't alone. My ex friend had a bottle of wine and she was drunk, I personally think she was putting it on a little. She needed the toilet but we ALL WENT before we headed back to the place we live. She was being a b*stard on the bus and then she pressed the bell so she could urinate, it was pretty far from our town. I refused to get off the bus (because we all went before we got on the bus), my girlfriend followed her so she wasn't on her own. She didn't go toilet when she got off, it was just an attention thing.
Then she said and did all this:
- Standing in the middle of the road saying she wanted to die (but when a car actually came she got out of the road), she also put my girlfriend in DANGER!
- She was saying the following to my gf: Amy (me) personality is full of anger, she's such an angry person. She can't smoke properly (that's due to not being a smoker!!). She needs to grow up. Our friendship needs a break.
I then told her that I no longer want to be her friend because she's such an horrible person and she's full of negativity. I've been polite about it and she's messaged me 4 times since I broke the friendship off, I've explained that I don't want to be friends.
She will not leave me alone.
Am I being too harsh?