Blackheads on face, temples, chin. Using cleansers, no relief. Treatment for acne and blackheads?

Hello, I have an acne question. A year ago, my skin was clear. I didn t suffer from any type of acne, anytime throughout the month. I am a 21 year old female with a very regular menstrual cycle. Over the last year, I have started developing blackheads on the sides of my face, mostly on my temple. My chin is covered as if every pore is clogged and no amount of cleansers has helped. I notice a positive change when I eat a healthy diet and exercise regularly, but they are never gone completely. I have taken alcohol, dairy and sugar out of my diet and still, these small bumps are still not gone. I am starting to wonder if I am missing an essential vitamin, maybe iron? I would love some input