Hi,
You do not sound overweight being 54kg at 5;3 , sometimes when you aren,t eating enough your body goes into starvation mode and it is impossible to lose anymore weight. It sounds like you are doing plenty of excercise which is good for everybody trying to lose weight or not but remember you are young and your body needs good nutrition so try to be sensible and not too hard on yourself.
Best wishes.
Angie