Acne can be stubborn many times and the treatment needs to be consistent since it is multi factorial. Make good changes in your daily diet and lifestyle as well.
Health Tips
Refer What Makes Your Skin Prone to Acne? Top 5 Causes of Acne" by Dr. Jolly Shah Kapadia - https://www.practo.com/healthfeed/what-makes-your-skin-prone-to-acne-top-5-causes-of-acne-14523/post
"Teen Acne: What Helps, What Hurts!" by Dr. Jolly Shah Kapadia - https://www.practo.com/healthfeed/teen-acne-what-helps-what-hurts-14525/post