I need help my girlfriend we're best friends and she broke up with me but still wants to be best friends help!?

so my girlfriend (who is also my best friend that i've ever had) called me wanting to talk to me about breaking up. I told her we could work it out but she told me that she was too stressed with friends and family and they just were asking for too much of her right now. She told me that she didnt want to tell me face to face today because I was smiling and today and she hadnt seen me smile. She said that she did care and im a very special person in her life as the same with mine. I did truely....love...or care as i like to say deeply for her. She said that just wants her best friend back but i told her I was always her best friend even when we were going out. I was deeply hurt and rasied my voice at her a few times im generally not a mean person but very kind hearted but when she told me its ok i know how you feel....and please dont leave yourself alone talk to your cousin hes probably been in the same situation I felt anger towards her. Ive know this girl for 3 years and ive always felt strongly towards her even when I didnt see her or talk to her....I just dont know what to do she's my best friend as she was before we went out what do I do she said she call me today to "check up on me" cant she understand im hurt i cant sleep or eat to much I still want to be best friends but I sill feel very strong could maybe someone give me some advice on what to do?