Another thing I might mention could be fluoride. Perhaps your water in Asia wasn't fluoridated but most likely you're exposed to tons of fluoridated water in the states. Not only drinking water (and tea) but also bathing in fluoridated water. Deteriorates teeth.
I would recommend using xylitol in your mouth to prevent more cavities from forming (and stop using fluoridated toothpastes) but I think the others have recommendations for letting the cavities heal. If you look through old posts in this and other teeth forums you should find some on this topic.