Girl problem... Should I "take her back"?

We have been talking the last couple of months. Last week she has seemed to have lost interest i me. At a party yesterday we talked and she said she liked me and another guy, fair enough. Later she seemed to dont want to talk to me, so i asked her if she really like me or not cause i dont want any bullshit, so she said ill just say no then (or something). So i said ok, fine. So im pretty sure she went home to amother guy, cause she left us, her friend said she would go there and she talked with him. Her friend achually said before that go out and talk with her or she will go and have sex with that guy. So idk if they had sex, but its most deg possible. Later when we met i just walked pass her, afterwards she was like wtf on message. I told her im tired of this **** so just forgrt everything. So today (day after) she has started having interest in me again? She wanted us to mert and she said sorry etc. She also said on message before i went to sleep at 5 am that she couldnt do this if i didint understand that she had depressions, which she told me like 2 hours earlier.

So i had kinda decide that im just gonna forget her. I liked her, yes, until what happend yesterday. I feel kinda betrayed.

Therfore my question is what should i do now that shes omterested in me? She is sorry, her friends says she is crying and that she likes me. Well im not that kind of guy that just accept things like this. However I stil like her in some way, but yeah. Advice?