I’m sure this is very frustrating. Please bear in mind that many parents don’t want to acknowledge the seriousness of a child’s problem, not because they are mean or neglectful but because it just hurts their heart too much. Parents also sometimes worry that their kid’s problem is their fault. They don’t know what to do about it and may feel helpless to change things. I don’t know what goes on with your parents. I do know you need to find another way to talk to them besides arguing with them or blaming them.
You need a thorough evaluation to see what you really need. Perhaps one way to persuade your parents is to ask them to allow such an evaluation. Tell them that if the psychologist agrees you don’t have a significant problem, you will let it go and will double down on your self-care and self management. But will they agree to treatment if the evaluation shows that you are on the autism spectrum or have a significant mental health disorder?
Other resources for you may be your school guidance counselor or a teacher you trust or your doctor. Parents will often respond better to another adult than to their kid. See if someone you trust can advocate for you.
I doubt online treatment will be helpful. You need a good diagnostic evaluation first.
I wish you well.