Number feeling in hands and legs. To do?

I am a mom of 2 kids.. Baby boy is 1 1/2 year old and is on breastfeeding.My weight is 43 kg and height is 5" 3.I used to be thin since my childhood. I am not a foodie and couldn't eat well. Since 5 months I am feeling very weak and getting tierd even for a small work. Now a days I am taking good food and milk. I eat non veg too twice a week. But there is no improvement in my body. I am very lean and weak. 15 days back I had severe numbness in my left hand thumb finger to wrist. By ngt it spreaded all over left side from shoulder to leg. I went to a nearby doctor and she recommended to use calcium and iron tablets for a month. She asked me to take thyroid and haemoglobin test along with calcium test of there is no improve ment. If there is an improve ment she told to use the same tablets for 3 months. After using those tablets regularly I saw decline in numbness. But today it is more from left shoulder to legs sometimes in right hand also. It is so numb and a rare feeling. What to do??