Why does my girlfriend hate me all of a sudden?

Firstly, I am sorry that you feel that your girlfriend has such strong feelings toward you. You are very valid to feel that way, but I hope you take some time to think about everything before you assume that she has these strong feeling for you. I always like to take some time to think about what lead me to think a certain way about situations, and when I am emotionally ready, then I think it is best to talk to the person involved. I would reach out to her and ask her if she could take some time to talk to you about how you're feeling. And I would address all your feelings on how they make you feel, rather than asking her "why do you hate me all of a sudden" as it implies assumption. I hope you get clarification.

usually people express negative emotions when their needs are not met or they feel unappreciated, misunderstood, hurt or overlooked. it may also be that "hate" is not exactly the emotion the person is experiencing, but they don't know a better way to let the emotions out. Or, possibly, the person doesn't even fully understand what they feel. The best way to find out is an open conversation. Unless there is an obvious event in the past that caused the intense resentment in your girlfriend, maybe she is trying to communicate something else, something that you have overlooked in the relationship. Speaking calmly and asking questions would most probably be a good way to start.

Personally speaking on my behalf. their not much that can be done.Hatred is a heavy word.for me hatred is someone who is disgusted by your presence you as a whole person. When things have come to hatred use the nearest exit sign. And don't try and figure out what has caused hatred.it's not for you to figure out.I have come to the conclusion that they themselves have experienced hatred from another and felt the need to pass it on. Distance yourself from such a negative word and be delighted you no longer need to be associated with a hateful person that feels the need to hate