Family doesent want me to fix my skin

I really hate when my older sister or any family in general tells me that my acne is only because am a teenager and that it'll fade with age,they said they wouldn't take me to a dermatologist,had this acne problem for three years,I recently took matters into my own hands and bought some tretinoin since it does not require any prescription in my country,but yeah,I told them that I didn't want to have to wait until am 20 for my acne to go away.