On desktop can't type chinese...anyway that is just terrible, did your sisters say anything to help you when your mum made the bad comments? If that is her attitude for so many years, then very hard to change, maybe just pretend you don't hear and don't get too upset la. If you can't afford to pay so much, then you cant, if she is not understanding, not muich you can do. I hope you feel better now after sharing this with us.