I'm so sorry.
One of my favorites was retired and sold at the same time as the horse I'd trained for lessons. :( I was crying when the owner told me she'd be selling him, but he was getting so old and probably would've had an accident eventually if he hadn't been retired, so looking back on it I'm glade they did it.
My other favorite was sold but the women boards him at barn. I was devastated at first, but it turns out she goes away during the Summer and lets me ride him while she's not there now. =]
Think about how happy her new owner must be! Apparently, she was a pretty awesome horse; think about how ecstatic you would be if you'd just bought her!