Try pantothenic acid (B5) in high doses.
I was told by a dermatologist, "I'm not allowed to tell you this, but taking pantothenic acid in high doses is the same as taking Accutane without all the horrible side affects."
I starting taking 12,000 milligrams of pantothenic acid per day. That's six pills, four times per day. Within three months, my skin was clear. I recommend the brand "Now" and you can find it on Amazon.
My skin was really bad before I did this, I mean REALLY bad, which was discouraging considering how clean my diet was. I don't want to post them publicly, but I'll send you my before and after pics if you want to see them.
I will admit that as a teen I used Accutane (which was $900 per prescription without insurance) and got the results of clear skin. But my dermatologist said, "You need to be on two forms of birth control, and have your blood drawn every two weeks to make sure your liver isn't shutting down." He said, "If you get pregnant while on Accutane or even soon after taking Accutane the baby will surely be deformed." Yikes. Knowing what I know now I would have gone with the healthier option, but at least now I can share through experience that this works.
If you're wondering why I continued to have acne even though my diet was extremely clean... STRESS. Yes, stress reeks havoc on your body, including your skin.
Moral of the story: eat clean, live clean, don't stress, and do some research before popping any pharmaceutical pills.