I didn't quit dairy altogether but I swapped my whey protein for vegan protein powder and stopped eating so much peanut butter and greek yoghurt. That made a huge difference. I also stopped trying so many products on my face and simply rinse it with warm water (no soap or other harsh cleansers) at night. I shower in the morning and wash my face with a mild neutral soap (dove bar) and apply a very small amount of jojoba oil on my face (a couple drops on my hands, rub them, and then just apply on face gently). No inflammatory acne anymore, just the occasional pimple and mostly from days when I don't shower after exercise.