You're almost doing the right thing, but 15 days is not enough time to start drawing conclusions.
The problem here is simply that what you lose in such a small amount of time, is for the most part water weight. Fat is persistent, but CICO is the right idea, and you should keep following that.
I consume ~ 900-1100 calories
1100 calories is taking CICO to the extreme, and I highly caution against it. You may not feel it now, but it will eventually lead to chronic fatigue, tiredness, and general exhaustion on a daily basis. You should find out what your daily calorie expenditure is, and undercut it by 2-300 calories. I have a feeling you've undercut it by about half.
with little to no exercise. I don't even do cardio
But why? Exercise helps you burn more calories. It's also how we help our bodies cope with the adjustments in weight, adjustments in weight distribution, and generally how we stay healthy.
Bottom line, and this bears repeating
15 days is not enough time to start drawing conclusions. Adjust your approach, preferably with the help of a doctor or a trainer. You'll find that none of them will approve an 1100 calorie/day diet. You still need nutrition. You still need vitamins and minerals to make sure your body can perform basic functions. If you carry on like this, you'll get fatigued, and then you'll get sick.
Since you seem very focused on belly fat in particular, take a look at this Q&A.
What exercises should I perform to reduce fat on a specific area of my body?
It's important to know the basics of how the body deals with fat.