Use of alcohol while on probation is considered to be a violation of probation.  If the violation of probation is proven to the Court, you are at the Judge's mercy.  The Judge can choose to do nothing, extend your probation, add conditions to your probation, or even put you in jail.  If you are on a MIP deferral status to keep the offense off your record, you could possibly lose that status.  I would recommend that you hire a lawyer if you can afford to do so.