Why my legs and hands are so skinny? Other parts in body are normal. (photo)

My hands and legs were so skinny.After went to gym it became normal except for the bones(example my fingers are so skinny , ankle,bottom of legs are so skinny)and my wrist and ankle are not having minimum muscle.Looking very old.Iin my family member's all of other having normal bones,..my body condition and every thing is normal except this problem( in my child wood i didn't have healthy food)...is any chance to get normal bones by doing any exercises or medicines. Kindly help me