seems to me going bk to China

is the most sensible choice, except you have to make up a story to tell your parents.

The cost is much lower, you can see your parents and when waiting for your visa you can visit friends etc etc

Unless you can find a flight from London to Halifax that only do a stopover at U.S. but transit passengers dont get off ...

Our cousin did not want to be a professor either, he ended up having no other choice if he wanted his green card.