I have tried everything you have, and I know your pain. First of all, give up on the aestheticians and cosmetic companies. Anything you can buy over the counter isn't going to work for what you're dealing with, I don't care what the Proactiv ads say, they're still just 10% Benzoyl Peroxide (the highest percentage you can buy OTC). The only person that can help you is a good dermatologist.
The ONLY two things that have worked for me are accutane and ortho-tricycline birth control pills.
I suppose the accutane worked better, but as soon as I went off it, the acne came back. I ended up going on it three different times. Finally I switched to birth-control for a more long-term method.
The thing with accutane is you absolutely do NOT want to use it if there is ANY chance of you getting pregnant. I was single when I was on accutane and the doctor made me sign a contract that I wouldn't be sexually active while I was on it. There is a huge birth-defects rate for babies conceived while the mother was on accutane.
I know how desperate you feel, and you may have trouble finding a doctor that will give it to you. But it can be a miracle worker. My skin has never been as beautiful as it was when I was on accutane. Good luck.