Starting again after adjusting

So I have noticed that this is not working therefore I will always write my diet the day before and stick to it. For now, I will eat 1200 calories maximum on the days when I have basketball practice- 1000 on the days when I workout without basketball- and 900 on the days when I do not work out. This will be very hard for my body but it should work there are people out there who starve themselves and eat 300 cal I can do this. I just really need to be strong.
Tomorrow: Gym cardio in the morning and 2 hours basketball at night. Calorie intake: 1200 maximum:
As soon as I wake up I will have 3 ice cubes
1 Protein shake at 7 am: 130 calories
10 am: 1 sandwich and jam which is about 170 calories and one apple which is about 80 calories
1 pm: fish filet and salade : 200 calories
4 pm: 1 kellogs bar for glucose
2 cups of cereal with 100 ml milk which gives 346
After practice I will have my protein shake

Total: 1066 calories and for calories burned I can say I will burn minimum 500 calories this means I created a 900 calorie deficit on this day.