Buddy, sounds like you got culture shock and the fact that you are checking out throntree forums for advice is a bit baffling as well-why are not you connected on expat forums like expat.com?
Look man, the metro is crowded but that is China. Taxi's are a bugger unless you know where you are going. If you are going to China and you have been here 20 times already...you should have learned SOME Chinese buddy. Its like anywhere in the world, fit in or f... off :p Not trying to be harsh but at some point you need to realize you need to change it up if you are not happy.
Crowds suck-its China
Things don't work-its China
bro-its life, keep your chin up, laugh at the setbacks and just be happy to be on earth and capable of making this awesome routine trip.
Life is good bud.