The question is DO YOU LOVE HER?
If you do you should try and win her back.
It is worth to have a conversation, calm, respectful, to understand what brought her to this decision.
When people are hurt they may say hurtful things, try and not fall into an argument, just listen to what she has to say.
You can say that you are sorry and still love her and want the relationship to succeed, and willing to invest the efforts for it to succeed.
She might still want to break away, give her time to reflect, think, be without you.
Then calculate the situation.
It is possible to win an ex girl back even after noisy break ups.