What is the ruling on an 'urfi marriage without the knowledge of the guardian, given that the guardian drinks alcohol and does not approve of the marriage?

Marriage is not valid except with a guardian (wali), and a woman does not have the right to marry herself off, nor to appoint someone other than her guardian to do so. If the guardian is not fit for guardianship due to disbelief (kufr) or due to preventing his ward from marrying (ʿadl), then the guardianship transfers to the next in line among the agnates (ʿasabat). As for the father drinking alcohol, this does not nullify his guardianship, because an alcohol drinker is a fasiq (transgressor), not a disbeliever (kafir), and the guardianship of a fasiq is valid according to the most preponderant opinion. You must apologize to your father and request a new marriage contract from him for your husband, with a new offer and acceptance and the testimony of two just witnesses. If the father refuses and prevents the marriage (ʿadl), you can request guardianship from the next in line among the agnates or resort to a Sharia judge.