Don't pack your bags yet!
The current visa bulletin has family category 4 currently processing applicants from November 1999, so there's still some time to go. Nobody can predict exactly, and future legislation may alter it.
The service centres don't bother processing the petitions for such a long time simply because there is no rush due to the long line. All that's happened now is the centre processed the initial I-130. You still need to get to the front of the line before any more action is taken.
If you were on the original petition before you reached the age of 21, you might have a claim on an immigrant visa despite the fact you are now an adult.
Your parents cannot file anything on your behalf unless they become and remain permenant residents of the US. If they did, you would be category 2a....and there is currently a line in this category, too. Future legislation may also alter this.