What kind of fat are you eating? If you are talking about vegetable oil, that stuff is high in polyunsaturated fatty acids, which are nauseating in quantity. Stick to the healthier saturated and monounsaturated fats, such as are found in butter/ghee, tallow, lard, bacon (or goose or duck) grease, etc. If you cook with them and use the fruit oils (avocado, coconut, and olive—which are much lower in PUFA’s than the seed oils), for your salad dressing, you will feel a lot better. Be sure to make your gravies and sauces with butter and heavy cream, as well.
While fat is quite satisfying to most people, some people need a little more protein and a little less fat to assuage their hunger. You may have to experiment a bit to find what proportion works best for you. You could probably increase your protein a small amount without risking getting kicked out of ketosis. There are various ways to calculate how much protein to eat. What we recommend on these forums is 1.0-1.5 grams protein per kilogram of lean body mass per day, but that involves knowing or guessing your body composition. Or instead of using lean mass, you could use your ideal weight as a rough guide. Alternatively, you could go on the Virta Health Web site and search on “how much protein?” which will take you to a table showing recommended protein intake according to your height.
Remember that meats are generally 7 grams of protein per ounce (or 25 g/100 g). If you have excess fat to lose, be sure to eat enough calories, because otherwise the body will hang on to its reserves, so it can get you safely through the famine.