The good news is that your bike (and most of the GY200 clones) has a frame that is based on the early XR200 (not the R version). The XR200 had twin shocks, but GY200 bikes use a monoshock (and usually a link); often the twin shock studs are still in place and support the rear rack.
Your bike could be made to fit the tank and plastics of any of the GY200 bikes, so it just depends on what you can find. Try searching
www.taobao.com with Google Chrome and allow your browser to automatically translate. Start with GY200 as a search term.