Can someone please help me with how to make low carb, fatless espresso?

Last week, I went for a regular health check-up and my doctor told me to cut down my carb intake. He suggested me to intake a lot more fibre, vegetables and liquids. One of my friends drinks a lot of Latte in a day and eat nothing else. She looks stunning, to be honest. So, when I researched on coffee, especially espresso since I like the taste of it, I got to know that espresso usually contains no carbs. 1 shot of espresso, that is unsweetened, usually contains 1 calorie, 0.1 g of fat and 0 g of carbs. And, brewed, percolated espresso contains 2 calories, 0 g of fat and carbs. So, I guess I am going to replace a good portion of my diet with a few cups of espresso. But, the thing is I am not good at making espresso. And, I know nothing about espresso machines . I tried to make traditional espresso after watching a few videos on youtube. But, the taste was way off. Can someone please help me with how to make low carb, fatless espresso?