Do I fill the defecit?

That’s more like it! You won’t lose weight without a calorie deficit, so I wouldn’t try to fill one if you’re not hungry. Make sure you’re fuelled for your hard workouts and so long as you feel like you have enough energy then I wouldn’t worry about it. So long as the weight loss is slow and steady, you should be able to manage it without losing power. Try and lose the weight in a month and you’ll more than likely lose some muscle mass.