My body does not re-act !

Hello. My weight is 57 kg while my height is 169 cm.

My trainer told me to lose 3.5kg of fats and add about 8kg muscles.

I am doing the exercises 3 - 4 times a week however, can not eat enough for my training.

Its about my apetite. My trainer told me that by the time I will increase my food but nothing changed. My apetite is still the same as well as my weight. I felt like whatever i do, nothing will change my body shape.

p.s i attended around 4 body pump sessions but with no point as well.

Any advice plz