My problem is that i don't like to eat , i can skip up to 9 hours or more without eating or drinking , what shall i do to eat , aged 20 (im very slim)?

Eat anyway: Eventhough you can "go" for many hours without food/nutrition, your brain and vital organs need a certain number of calories from protein, carbs and fat to function normally. This means to allow your brain to think/operate at it's maximal capacity, allow your heart to beat and your skin and bone to maintain their health. Try multiple small meals/snacks or protein bars throughout the day.