If you want to be with her, just be prepared for everything you just described to happen again. Even if she stays clean, she will always be an addict. If she is up front about herself, attending Narcotics Anonymous, hanging out with healthy friends, that goes a long way toward getting better.

What you have described is a relationship with a liar, addicts are. She is also given to violence and self-harm. Being an addict also means that she is very intelligent, probably beautiful and creative too.

What do you want for you? I'd find out as much about drug addiction, its impact on relationships as I could. Then weigh the pros and cons of being with her.