depends what you drink.............
if its beer/lager/cider/liqueur your blood sugar will want to rise with the carbs that are in them.....so this could be making you lethargic.......
best thing to do is test your levels during the times your having a drink............
alcohol can and will drop levels,how much and how fast again depends on the strength of alcohol your drinking, but for a type 2 on no medication at least this shouldn't be a problem as the pancreas will respond accordingly....
what's your poison?