<human>: So I've known this girl for 3 years now
When we first met she was in a relationship with this verbally abusive guy. Last summer she broke up with him and she needed me for support.
I liked her, but I stayed away while they were together. I respect relationships, even if they're as unhealthy as theirs was.
Well I was there for her and we started going out like 2 weeks later. Things are going good, she's finally starting to be happy. I treated her with the love and respect she deserves. After like 2 to 3 months we have sex for the first time (it's my first time ever) and we admit to each other that we love each other. 
Now it's like 3 weeks later and on Friday she starts acting ask weird and distant. I keep asking her of something's wrong and she says that everything's fine. 
Well at the end of the school day she brings me down behind the school and says that "she's depressed and she can't be with me right now"
I'm fucking heartbroken. And she leaves with a quickness
I'm talking to our mutual friend later and she says that my now ex has been missing her ex that she broke up with (the one that's verbally abusive)
She's de-friended me from all social media and said she doesn't want to talk until she has her life figured out.
She said that it's not my fault and that it's nothing I did.
What do I do now?

Can you summarize the given text in a few sentences?
<bot>: my girlfriend broke up with me. Mutual friend says that she misses her ex. She said she's depressed. What the Fuck do I do?