You have a number of resources at hand...

if you are still in school, talk to a guidance counsellor. There are school psychologists. They may be able to get a referral to a psychiatrist or psychologist outside the school system. They also can act as a go-between with getting your parents on board.

Similarly, your family doctor is a great resource.

Find out if either of your parents have an employee Assistance Plan (EAP). I've talked about these before. This is NOT to be confused with the benefits plan. EAPs are instead 'clearing houses' to resources - including having psychologists to talk to 24 hours a day. I called my own EAP once and they helped me with not only someone to talk to about stress but also legal counsel. An EAP is a very good resource. Most companies have them. If your parents are unsure, this information is available with their human resources.