<human>: Can you give me a shortened version of the text?

I asked my girlfriend who she was texting and she got very defensive and said it was just a coworker. I let it go at first but I couldn't stop thinking about how she reacted, so I asked to see her phone. She demanded to see mine too so I showed her mine then she didn't hold up her end. A fight ensued and she tried everything possible to not show me. I finally got her too and it was a guy and all i saw was him saying "i miss you lets meet up" and her saying i miss you too and planning a time.
   I then stopped reading and said i want to break up. She swears she didn't cheat and didn't plan to and tried grabbing every knife in the house. I spent the next two hours trying to stop her as she begged me not to leave her. Some more details - we've been together for a year and live together.. Please help. What should I do?
<bot>: I found my girlfriend texting another guy saying "i miss you." I told her I wanted to break up, she then threatened to kill her self and swears she didn't cheat.