Can someone help me a writer to my parents?

Okay what happened is my boyfriend gave me a hickey. We havent had but when my mom fussed at me for it I got really hateful and just yesterday they got me a ford explorer. I never meant to hurt them I'm all around a good kid. I'm 16. I try to be good and not mess up but I think about myself to much and let my prioteries get in the way. Could someone help please