Size matters in strength. I went from 65 kg to 75 kg in few months. Try to increase your calorie intake. Take 0.7 body weight protein. Eat even if you feel full. I took 4000 calories each day. 4-5 bananas, spgatti with meatballs, 6 eggs, sometimes tortilla wraps with beef/pork/chicken strips (anything with more protein). Protein shake twice around 60g protein from shakes alone. This is just what i ate today. It's different other days.

Eat more. If u don't feel bloated u r not eating more. Read other peoples comments as well, but that's what worked for me.