I've loss weight and been very sick for the past 5 months, i have been tested for alot of things but the ultrasound showed a cyst
You can read about hepatic cysts here:
http://emedicine.medscape.com/article/190818-overview
Generally speaking, simple cysts are ususally nothing to be concerned about unless you're having symptoms. I advise that you read the article to get a better understanding of the different types of cysts.
Mike