Im having pain on the entrance of my vagina,and what looks like a coldsore,i have no discharge, just pain if i touchit,and the only thing that i think caused the pain is rough sex for a week straight.im a minor,telling my mom is not an option?

I answered you question already. If you cannot see a doctor because of your mom, you need to practice safe sex from now on. Do not have safe for at least one week. If the vagina lesion is from rough sex, it will heal by then. Herpetic lesion(s) is also healed without treatment by times but it will recur. Take this as a personal experience, practice safe sex otherwise you may get more serious STDs.