Please Provide Me With Advice On What I Should Do

My girlfriend broke up with me a couple of days ago, however I am still in love with her and want her back. A little background information, we have been together for about 9 months. Recently, things have not been really good between us, we have been short fused, distant, non-affectionate with each other, and arguing a lot. We have both been under a lot of stress; she has handed in her masters thesis, and I have been under tremendous stress at work. So, this past friday, after having fought on silly things and have not spoken (I was working evenings and we had agreed to take time apart as we needed to decompress), she told me she needed time for herself, that she was not sure if our relationship is what she wanted, and that she was tired of us fighting all the time. I explained to her that I loved her and that I was sorry for being the way I had been and that time apart might be good, however I still wanted to pursue our relationship. I should also precise that on this same friday, we were supposed to spend our vacation together. Now, I am alone at home and she is spending time at her sisters out of time so that she can "find" herself. I sent her an email explaining how I felt, that I understood that some of my actions and my behaviour was not the best in the past couple of weeks and that I wanted to make things right. It has been 5 days now, and I have yet to hear from her. Before she left, she said that maybe when she got back we might chat and see how things are. I am currently going crazy as, although I might not have told her and shown her, I am madly in love with her. She is all what I think of, pre and post break up. One of my major mistake was never telling her that and to have taken her for granted.

My question to you guys, what should I do and what are the odds of her coming back to me? I had the oppurtunity to chat with her sister and the sister said that she would do her possible to get my now ex to give us a last chance.

Please help me and provide some insight!