How can I keep her from leaving me?

[James]

This girl started working with me a coupe months ago. At first, I would hangout with her and a group of kids, but eventually it would be just me and her hanging out. We started getting intimate and we found out we have almost everything in common.
Everything was going well for a while, we would hangout late into the night and I invited her over at 3 am once, she slept over & we had sex.
Now the problem. I noticed on facebook that she was hanging out with some other guy. I started getting suspicious, but i didnt say anything. Then i find out that shes been staying there for the past few days and shes been hanging out with him alot. Then i notice on twitter, him posting "the past few days have been great, i like you, you make me happy." Couple days later, he posts "my boo is having a bad day and its making me upset", and she was in the er with strep throat..
So now i call her out on it, I flip **** and say alot of mean things to her because it seemed like shes been lying to me. She then explains that he lives in an apartment complex with a few of her friends, and that he had some other girl there with him that he was talking about in his posts. I kept texting her and second guessing her, and finally she lost it. She told me she was hurt that by what i said and that i didnt trust her. So our relationship pretty much ended there.
I see her at work the next couple days, and we talk here and there. But the last day of work, she came up to hug me before she left. I told her to come over later that night, but she texted me saying we need to talk before we do that. So i texted her a couple times asking to talk, but i got no response.
Any advice? How can i get her back?

[Veronica C]

Respect her decision and move on...