Struggling with Depression and Unsupportive Parents

I've struggled with depression for a couple years now but my whenever I've tried talking to my parents about it, they never take it seriously. They've accused me of doing it for attention, when really it was a cry for help. Instead of helping, they'd point the finger at other people that could be causing me to feel this way. They don't understand how one day I could be completely fine, and the next, be at my lowest.