I have read through your thread to get some information about your feelings. I can put a shoe in your feet and partly understand how you feel about the way some expats treat you. And I hope my share will help you feel better.
I am not so sure but I think maybe you have expected that foreigners will be kind (with your past experiences with some nice Americans) then when it came to nothing like this, you became frustrated. I think with some expats you met, it does not mean all expats are not good and do have bad thoughts about our country and people. Maybe you should be more optimistic and do not get yourself down by the ones you do not expect to meet.
I do not know whether my comment is good for you but hopefully, it will make you feel better! :)