Hi, I was so sorry to read your post; you must be very frustrated, and you are much to be commended for continuing to try such a lot of things, and not giving up. You sound very strong. I have also suffered from Acne
most of my life, and still, at age 36. Very frustrating.
The only thing that ever worked for me, and it worked 100%, was an all-raw diet. Well, probably, it was more like 90 or even 80%, but I was always shooting for 100%. This diet was difficult to stick to, time-consuming, and sometimes dull if I didn't give it the time it needs, but I never felt healthier or more beautiful in my life. I literally looked like a model. Even my regularly clogged pores on T-zone that I daily extract sort of "harmless" white small oil plugs from stopped filling and remained clear. My weight was perfect, my skin flawless, even my emotions were in check and under control. No foul breath, just a clean, light, energetic feeling always, and I only needed five hours of deep sleep a night! My bowel functioned very well, twice daily at least, and stools were of great "quality".
With all those benefits, you can see that unlike you, I am not a strong person, and after several months of this wonderful state, I lost the self-control to stick to it, and hence, my issues came back. Still, I thought I would tell my experience here, if it might help you.
These days, going raw is very, very popular. There are many books you can find with recipes that range from easy to gourmet. Here, in Los Angeles, many health food markets have a raw food section where you can buy meals. Even in Austin, Tx, the Whole Foods market there has one, too, with a very popular "cheesecake". Sometimes the ready-made to-go versions are a little self-defeating, since the idea is to have as fresh as possible food, complete with enzymes and nutrients. But, if one is very busy...
My mom is a colon therapist and tells many horrors of what cheese does to the bowel, so no doubt that would be a no-no for you. It's also my downfall.
Lastly, do look at your makeup. It's probably not this simple for you, but off raw, I still did notice a great improvement when I switched to Bare Minerals all natural mineral, non-comedogenic makeup. It actually has a slight improving effect in makeup quality. You can get it online or at Sephora. I really love this makeup. Even in hot, humid weather, it doesn't make me break out.
I wish you all the best, and hope you find an answer to this challenge!