my parents have put me in a position where they think i'm overreacting when i address that i might have some sort of mental illness. is there an alternate way to get diagnosed w/o my parents knowing?

If your school has a counselor, you can always go to them and express your concerns. This would at least get the ball rolling. But that doesn't mean that your parents HAVE to send you to a doctor to get a diagnosis. It just means that your parents will be confronted with the information from another, credible adult. Another option is bringing the matter up with your physician when you have your next check-up. The only other option is to wait until you're 18, and even then your parents would have control over your insurance (provided you're on their plan).