Have you ever thought ‘I’m sticking to my calories but my weight loss has slowed, what the hell??’
Chill! It’s fine, what’s happened is that after you’ve lost a substantial amount of weight your body will become more efficient at using calories and also encourage you to use less.
If you had a twin (your lifestyles are the same) who has weighed 70kg for as long as you can remember and you have lost a lot of weight to get down to 70kg your metabolic rates would be different!
Your body reacts to your substantial weight loss by making your body use less calories. So your their Metabolic Rate (BMR) might be 1600 where yours might have down regulated to be 1400!
You could halt your weight loss for a bit and allow your metabolic rate to recalibrate up (a diet break).
This is great for mental and physical reasons. Then you can crack back on with the diet.
Know that your body is going to guard against weight loss, lethargy (to make you you conserve energy) hunger (to get you to eat more etc!