Im guessing at that weight you're around 5'5-58? If so you need too be eating ATLEAST 3100 calories a day, preferably 4000. I weighed 135lb and now up too 165lb, since i was soo= underweight the fat (which was miminal up too about 155lb) eating 4000 i was gaining about 2lb per week. (i noticed your in kg, know that im in lb).
Buy a digital scale, get friendly with high calorie foods (whole milk, bananas, peanut butter, oatmeal) if necessary, you might not have built the appetite to handle 4000 calories a day, get a good mass gaining like Serious Mass. Though i find it too be costly compared too buying my weight in food (high cal foods are pretty cheap) you can also blend them.
3 cups of whole mik = 450 calories
3 bananas = 360kc
6 eggs = 420kc
2tablespoons of peanut butter=200kc = delicious 1430 calorie shake.
Just the advice from someone who uses this strategy too bulk and continues too.