My dad is hounding me because of something. Nedd advice

So my dad keeps hounding me about a car i just purchased. Because the interest is high because my credit score is so low. So i purchased the car for 5000 the interest is 28% of that so i think about 18000 for the car and its a 2009 which is expesnive as idk what i made a mistake but i cant fix it its done deal. I screwed up but everyone makes mistakes in life we just learn from them. But im tired of hearing it now... its getting on my last nerves... i needed a car bad my 2001 is going out and needed some quick.