you've been in the states for 5 years and it's natural for typical parents to expect financial support from you. are you a student or are you just working? have you been home since you came here? do you communicate enough with your parents? do they know what job you do, how you work, how your living conditions, etc are? as others have pointed out, i feel like it's a communication problem, not merely financial. talk to them and explain everything. they are your parents and they'll have to understand.
i talk to my parents, they know what i do, how i live, how much i earn and all that stuff and they never ever ask for a penny. all they say is spend for your needs, save whatever is left and spend that for ticket to home as often as possible.
talk to them, that's the best solution.