Losing her trust

The problem is that two days ago my girlfriend or actually my ex we broke up like A week ago because She thinks that we’re not good together that Our chemistry is not matching and you have different characters but actually this is not the problem the problem is that she called me two days ago and told me that one of her group friends in the University try to touch her try to ask her for a kiss or a hug and she refused as she still loves me and she told him that and after that he he tried to be aggressive and she refused and she ran away and got back home and then she called me while she is shivering and nervous and she told me every detail and what happened and then I was a little bit confused as she broke up with me and I thought that her reasons was not fair but actually I tried to calm her down and I told her to to rest in bed and to drink and eat I was trying to just calm her down and after that I was gonna talk with her to the next action with this guy but actually after like two hours she started to hate me as she told me that my action was not enough and that I Should’ve done a better action and that I’m not a good person and I don’t love her and I don’t care for her She told me that I am a cold guy and she hate me as I didn’t take enough action and then I tried to call her a lot to tell her that this is not true and I care for her but she actually closed her mobile phone for all the night and after that I got panicked and then I searched for this guy‘s number and I got it and I called him at 2 AM and I insulted him badly and told him that i will put him in prison if he ever touched her or talk to her again . After that he sent to me WhatsApp messages telling me that he will not ever talk to her or look at her or touch her again and that he is so sorry then I took a screenshot of this chat and I send it to her and after the night I went to her House and told her that I am here please I want to see you but she refused and she told me that I have done that after she closed her phone and told me that my actions are not enough and she thinks that this action is not coming entirely from me after that she told me I don’t wanna talk to you again and changed my nickname on Facebook to my real name not love and then she told me I don’t want to talk to you please get away I hate you. then I called the guy again and I asked him to meet and then we meet and I beat him up and punched him in his face and after that I I sent her a voice messages telling her that I have punched this guy So that she can love me again or trust me but actually she didn’t she stoped talking from yesterday and just she thinks I’m not a man and I’m not trust worthy I’m not giving her what she deserves then I tried to reach out best friend but actually her best friend is taking her side and she asked me not to call her again and I’m now out of ideas I want to get her back but I don’t know how to gain her trust back.