To me, it sounds like she was upset, but then decided she was going to get everyone on her side by making it worse and saying stupid stuff like "you should die." Then, I think she decided that even though she wanted everyone to hate you, she still liked you, so she came crawling back, not letting others know. If you wish you hadn't called her fat, I would tell you to apologize for that one thing, and walk away right after. Don't date someone who tells you to die, then comes crawling back. Hope this helps!