Same situation is here.
Regarding to carbs, try to make it around your workout and on breakfast. Assuming you wake up on 06:30AM, then:
Breakfast: Complex carb + Protein
Lunch: Protein + Healthy fats
Pre-Workout Meal: Complex carbs + Protein
Post-Workout Meal: Simple carbs + Protein
Dinner: Slow digesting protein + healthy fats
BTW 400g of carbs seems very high amount, what are your stats?