Nothing grits my girdle more than one coming into a Water Fast as obese thinking they will be like other fasters.
You have a coated tongue and oily skin ... well you have TWO HUGE SIGNS that your body is doing what it needs to do. Having the expectation you will fast like others is the wrong approach to this and will likely only set you up to fail.
You are a unique human, whose body is like no one elses. With patience, time, and educating yourself with what fasting really means for your body will get you much farther and more successful than thinking you will be like everyone else.
Be extremely happy your tongue is coated and your face is oily ... this is great news!!!!