Upvote:5
Under Section 212(a)(9)(B) of the Immigration and Nationality Act, if you overstay in the US, you begin accruing "unlawful presence" after you turn 18 years old.
If you are unlawfully present for six months, you attract a 3 year ban, and if you are unlawfully present for a year, you attract a 10 year ban.
Based on the information you've given, it appears you remained in the US for more than 1 year after your 18th birthday, and therefore would be banned for 10 years.
It is possible to get a waiver from the ban in only a very few circumstances; you would need to be able to prove that you have a spouse, parent or child who is a US citizen or permanent resident and would suffer extreme hardship if you were not to return.