Don't feel sad

I am a post-doc also. Fortunately (if you think so) I got I-140 approved before graduation. For me GC is nothing comparing to having a permanent job. I do think people will have more opportunities in China than in America. Having some work experience here will help us find a good job in China although not easier as before, but we will enjoy life there after all we grow up there.
Don't feel sad. Think about positive side. Enjoy each day!!!