Nature is the best to reduce acne problem and skin problems in general. Not only skin but also many other parts of body need things come from nature.
Talking to skin problem especially acne in any age, I recommend 2 things that you might concern.
Firstly, use the white egg with honey is the most common way of my to have better skin condition. The white egg has function to recover damaged skin and tighten pores (this is more powerful than you ever thought because if pores are wide, they will attract more dust from the polluted air, and of course, it brings about acne and many other dangerous disease for skin like skin cancer). How to do it? it is really simple, you just need to separate the white egg and the yolk from each other. Use honey and the white together by mixing them carefully, apply on entire your face not only the damaged areas. Let it dry for 30mins, then re-wash with water. Then apply the yolk again, let it be in 15mins, then rewash again. The yolk has function to support what the white has done before, tighten the pores and protect your skin from sunshine just in case you have to go out many hours.
lastly, you need to steam your face usually. The best way to steam is using lavender oil with 3-4 droplets and hot water. If you do not have enough time, you can do it more simple like hot water with salt. And more complicated is with herb, but I think this will be the best if you do with herb once/weak. And steaming needs everyday. Steaming helps widen pores and the droplets bring out dust that exist in pores for long time outside with polluted air. And it also help your skin absorb more nutrients from mask that you apply on your face. I think the best way is to steam before doing skin care.
Hope you get what you want!
BTW, dont forget to drink much water when you can, and avoid sunshine or polluted air as much as possible.