I too have been dealing with severe Acne off and on for the last 4 years (began when I was 19). I've been following the nourishing traditions diet (aka Maker's Diet by Jordan Rubin) and have noticed more than anything drinking kefir and cooking with or even ingesting a spoon full of Extra-Virgin Coconut Oil (EVCO) right after each meal has been really helpful. In terms of kefir, I drink 1 cup when I wake up and 1 cup before I go to bed of Organic Pastures Quephor, which is sold throughout health stores in California or you can order it online via organicpastures.com. Kefir has natural Antibiotic properties and EVCO is amazing for the skin and has great antioxidant effects.
Acne is basically a way of telling your body it is overly toxic and cannot eliminate that toxicity naturally through the digestive tract thereby eliminating through the skin.