Ever since easter my girlfriend has been avoiding me. She focused on her favorite anime so she doesn'the have to remember that she is depressed. I try to make her tell me why she is avoiding me but she always answer with "i'm fine". She also wants me to let go of her. She has been through a couple of depressing situations. But I never imagined that she would avoid me a lot.

I can't say I know what's going on, but just be there for her like you always have. I'm also worried. She "wants me to let go of her." That sounds like she might attempt suicide. I may just be looking too much into this, but better safe than sorry.

If she needs space, then maybe you should give her some space. I'm not saying that you should give up on her, but a bit of space can do wonders.

However, if you think she might be making contemplating suicide, then I think you should tell her parents/ loved ones. It's better to not be friends and alive than be friends and not alive. It's a selfless love, one that extends far beyond our own needs.

When one becomes depress, they need to escape for awhile. Be it with music, books, movies, video games, anime, etc.
But to much of this can lead to being withdrawn from the world. People like this forget the world around them, and soon rely on a fantasy world. The only thing you can do for her is to wait for her.. If you seen the music video of Me!Me!Me!, it also shows a similar struggle of people go through to this. This brings a false happiness, and all I can say is when she decides to try and fight out of it, don't let her fight it alone, be there for her.. If that makes sense.
so um, yeah.