Jonathan,
Since you've been banned for 3 years, you can apply to the court which sentenced you in the first place to get your licence back after 2 years. You've already done 19 months so you need to wait 5 more months before you can apply. Make sure you tell the court that you've completed the drink driving rehabilitation course and send them the supported documents. It is however at the discretion of the court to remove your driving ban.