welcome to HealthcareMagic
Since your height
is 156 cms the ideal weight in your height is 49-61 kgs so i think the previous weight of 55 was well with in normal limits.If you have lost a few kilos then it is fine but if you lose 10 kilos then it will be 45 which will be under weight and can precipitate diseases and generalized weakness( nobody advised about this).If it is just fat
you want to lose then it can be done with exercise like swimming
;jogging;skipping also severe dieting
is not required in your case.Lastly the most important thing is you are not going to be on strict diet lifelong so whenever you stop dieting you will put on weight more than what you have.I would advise you keeping your age of 14 yrs in mind
please don't do severe dieting as now is the time of development of your body which may be affected due to weakness if it come on with severe dieting.Take care;consult a doctor if required;think logical before you act.