How can I visit a doctor n check my mental health if my parents won't let me?

No idea how blogs here work, that's it! I have a lot concerns about my mental health, but my city is too small, I don't have any friends irl and my parents think I'm fine and shouldn't go to a doctor. I really hope there's nothing wrong with me, but still I'm kinda nervous to live in that state yk...

Thank you beforehand if someone's gonna respond!