My parents opposed it too, and I got no support (financial and emotional) whatsoever. I took out my own private loans. Now I wish I had known better and that I would've done it some other way. Because living with heavy school debt is extremely burdensome... you have no idea. I'm going to have to live with this burden for at least the next 15 years, and it truly feels like an invisible prison.
You say you're a citizen.. why not try ROTC or OTS and try to become a military pilot? If I could go back in time, that's how I would've tried it. I know it's a big commitment, but I would gladly give 10 years of service if it meant being free of flight school loans!
As far as your parents... they definitely are misinformed on some things, but correct on other things. My mom especially used to feed me all kinds of crap like "I heard you can't become a pilot if you wear glasses." "I heard you can't become a pilot if you aren't from the military." "I heard you can't become a pilot if you're a woman." "I heard..."
It was hard for me to communicate to them about this whole flying deal because they are so clueless about it (I was too, but not as much as they are.) When I finally became a regional pilot, my mom confided that even right up the moment of being hired by a regional, she thought I was going through a phase and that it wasn't really going to happen. Now my parents are really proud and supportive, but it's because I proved to them that I was serious about it and that I stuck it out and made it through. although, they still dont realize that I can actually fly the plane.. they think I'm the radio jockey or something.
I think you will just have to convey through your actions if you are serious about this. the only thing is dont take out any loans!