My parents had me placed on an ADHD medication and I don’t like the person it turns me into

I’m 15f and I’m on medication for adhd which my parents insist I must have because my grades are shit. I personally don’t think I have it but they still got a prescription for a medication I can’t remember the name of. It completely changes me and I’m just extremely zoned out the whole day. I barely talk, have zero interests in any of my hobbies anymore and I no longer make jokes like I used to. I’m also completely unaware of anything going on around me I’ll be having a conversation and just walk away when the other person is mid sentence completely forgetting I was even having a conversation. I’ve expressed these concerns to my parents but since my grades have gone up they insist it’s working and even had my dosage increased despite me telling the doctor about the side effects. A few days ago I started hiding the pills under my tounge and throwing them away and I feel amazing not being under the effects of it

However my parents are starting to suspect something and it won’t be long before they find out. What can I do to insure I won’t have to take them again