You have to bulk when your goal is to add muscle to your frame and you lack sufficient fat stores to recomp. It’s that simple.
The populations with the greatest capacity to do a body recomposition (simultaneously gaining muscle and losing fat) are new lifters and obese individuals. New lifters can do this because their capacity to add muscle is so high, and ...
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
“Should I continue with the same routine I had? o Should I change something?”
I stand by some of the answers that you can do compounds lifts or even a full body work out to make it more efficient. Compound lifts burn more calories in a sense as it recruits more muscles more work.
Progressive overload is an important principle in training and you can do so ...