Leave all your love and your longing behind...

So, Li contacted me tonight, and asked if she could come over. I was surprised and happy about this, so I said yes. Then she messaged me and said that she had to be home around 09.30 pm, and I was like, oh, uhm, okay, but I still looked forward to it. Then I got another message that said that she had to cancel because her brother got home and she had to leave earlier, and if we could hang out tomorrow. I haven't answered back yet, because I am pissed/hurt.

I'd just gotten myself ready and I really looked forward to her coming over and then she cancels on me, when we haven't even seen each other in ages. Yes, she asked if we could hang out tomorrow instead, and that is all fine and dandy, but she can't just ask me to hang out tonight, suddenly and out of the blue, and then think everything is fine when she cancels. This is so typical, so very her, and it is one of the million reasons that I decided to break off this toxic friendship in the first place. I haven't asked her to hang out since what she did to me on News Years Eve, and I'll be damned if I'll let her into my life again if she keeps doing this shit. For those of you who don't know who she is, Li is/was my best friend since we were 6 years old; we were in the same class, on the same cheer-team, together all through high-school, and very close; and we had fights, so many fights. We were like Yin and Yang; she was blond, popular, confident, and I was darkhaired, unpopular, shy and insecure. Despite all of this, we kept coming back to each other, or rather, I kept coming back to her, even when she broke up our friendship and was bad for me. Around her, I was always jealous, self-hating, insecure, and always, always second best, but I still had a good time with her. Basically, I depended too much on her, and it hurt me. After she had broken off our 'best friendship' as she called it, for the second time (the first time being when we were kids) we still occasionally talked, and I was still depending on her. Then, after she did this to me on New Yorks Eve and ditched me for her new friends, I began to realize (after a breakdown and a talk with my dad) that our friendship was over, and that I would never depend on her again. She has always been bad for me, but I loved her, and depended on her, so I let her treat me like she wanted. Now she wants to talk to me again, and she expects us to just be 'casual friends', but she has no idea that it probably can't be like that for me. Either she is a close friend, a best friend, someone I can't depend on, or she is out of my life. I am willing ot just be casual friends, but I don't know if I can do that.

I still love her, and we've had so many good times together, but I just don't know.

TL;DR: what do you guys say?