Hey KC! I feel your pain. Acne is a terrible trouble to have, especially since you started having it at 23. In your case (since you mentioned white coated tongue & yo-yo'ish acne), I think your body is trying it's best to clear out, and clean itself. Cleanses is a good way to go about this. Have you ever tried The Master Cleanse by Stanley Burroughs? It might be just what your looking for. If you've never tried it, go to the nearest bookstore ASAP and pick up a copy!! Get as much information as you can about it- Google it, Youtube it. The cleanse is suppose to last a minimum of 10 days, in your case I would suggest stop the cleanse once your condition is completely gone (you must stop all other cleanses once on this cleanse).
If you HAVE tried this cleanse, move on to your diet. Here is an interesting article about diet, http://www.freeacnebook.com/
(lots of information, click around). Also a fruitarian diet might help ( http://www.fruitarian.com/
), until your condition is gone, and by then you might not want to stop. Green tea also helps inflammation. Remember, listen to your body, don't overeat. Lastly DON'T THINK ABOUT IT! STOP WORRYING! Yoga helps calm the mind. You have to love your body and skin if you ever want it to get better. If someone you loved got sick, what would you do? Don't hate your body, it only wants to do you good.