Why does my girlfriend hate me all of a sudden?

You could most definitely ask her. The only true way to know is to ask. Think back to see if you've done anything hurtful or unkind.

Maybe it's something you did. Knowing or not knowing. Maybe she expected something from you or expected to act accordingly but you failed to catch it. Best guess is to go and talk to her. Ask her, what went wrong and how you can correct it. Trust me on this, always put the blame on yourself no matter what.

Best answer I can give is to talk to her about it. Only she would know why and she would be your best source

Have you asked your girlfriend? It is best to explore your feelings with your partner. There is probably something going that could be answered with a peaceful conversation.

Often people don't shift character all of a sudden without reason, even if it may seem that way. It may be worth just facilitating a discussion and expressing your feelings about her attitude shift and how it makes you feel. This can also give her an opportunity to open up about concerns she may have, or a possible cause for this. The most important thing is to have a calm, rational discussion about it and both express how you feel so that you can resolve the issue.

1) I am not perfect, i did something wrong 2) she is not perfect, bear with it, must be a PMS thing 3) There is somebody else

it's because either she found something wierd abt you, or may be she likes someone else, whatever it's you have to fix it.

can't really answer that, only you can answer that. maybe you did something that she didn't like. remember, communication is key.

Maeby she has something that she wants to tell you but just not yet know how to tell you . I would just inform het everyday that you love her and that she can always talk to you about anything .

It may not be "all of a sudden." Sometimes people keep things bottled up inside until the pressure becomes too much, and then it comes out all at once. Talk with her, gently but directly, about how she feels to find out if this is the case.