Force yourself to stay awake during the day. Chances are after a few days, your system will be so exhausted that you will be able to fall asleep at night. If you let yourself fall asleep during hours when you would not normally fall asleep (say, daylight), you're gonna mess up your schedule.
I came back from China this summer too, but I shook jet lag off after about a day. All it takes is some pre-planning (staying up the night before you leave), willpower in staying awake, and an exhausted body when it's time to go to sleep.