How can I save wet cookie dough
You could go ahead and add each of the other ingredients (other than the milk) again, doubling the recipe. 

If you really want to get fussy, you probably should follow the recipe instructions regarding "creaming butter and sugars"...etc. with that second round of ingredients, but honeslty cookies aren't that particular about technique, so I would just dump them in and mix-em up. Your result should be quite reasonable.