I do feel sorry about that, C hing. As long as you loved her and had good time with her, money was not the concern. This story only tells us that we things may not work well as we think. I had similar story, but only the case no money involved. Any long distance relationship would have this potential problem. Two people can't really be together, it's hard to truly understand each other. It's hard to determine right or wrong. As we can't be with the girls all the time, whenever she needs someone, someone would take over the place.
Unless you can really be with someone in a different location, otherwise, it's really no good result for long distance relationship.