I've never had Acne like you have, but I have experienced some Acne due to a hormone imbalance. I apparently had a benign growth on my ovary that was pumping out too much of one hormone. I had to have surgery for it and once it was taken care of... Acne is gone. The acne I had was the worse I had ever had, I've had pretty good skin my whole life. This acne was bad enough to leave scars. I know you are a male and have no ovaries, but guys can have hormone imbalances as well. Testosterone is usually the acne creator, so too much can cause problems. All the detoxing in the world will not address a hormone imbalance.
Anyway, I did a lot of natural things while I had acne and I know you are probably the expert on skin creams and such, but I didn't notice any of the following things on your list of things you've tried.
Jojoba Oil: I know it is an oil and those of us that have ever struggled with acne run at the site of pore-clogging oil, but this one is different. Jojoba oil is almost identical to the sebum(sp) oil that our bodies produce. When applied to the skin it works according to how your skin is already functioning. For instance, if you don't have enough sebum, it provides more. If you have too much sebum, it balances that out as well. It took me a while before I tried this one because I was really afraid of making things worse. So I tried it one just a small area of skin. After a while, I was seeing improvement. I now put some jojoba oil in my skin lotion. It also has antibacterial properties that are effective and since bacteria is a factor with acne, it helps there too.
Also, I had a friend once who would break out pretty bad as a reaction to strong negative emotion. She would get depressed, she'd get acne, she'd get stressed, acne and so on. She starting taking supplements to help out her adrenals and then learned about to cope more and she greatly improved. Basically, attitude does really affect us. I've suffered other health problems and I noticed that one of the best things I could do for myself was to learn how to be at peace. This doesn't cure things by itself, but if you are in a "good place" than I believe your body can focus more of it's energy on any ailments you have.
Detox Bath: I know you've said that you've done a lot of detoxing, but have you ever had a detox bath? I love this one! I use Epsom Salts , dead Sea Salt s, and sometimes baking soda. I know that most of us think that salt is very drying. I guess it can be in excess, but these baths have made my skin feel great. There are different ways you can combine these things, but I usually put in 2 cups of the Epsom salt, 1 1/2 to 2 cups dead Sea Salt (any kind of natural Sea Salt will do) and about a cup of baking soda. Soak for 20 minutes and then rinse yourself in the shower. Epsom Salt is excellent at drawing toxins out of your skin and the dead sea salt has many curing properties due to the high amount of minerals. Baking soda cleanses as well but it also makes the bath more alkaline. You acne could be due to having your skin too acid. Anyway, if you try this, I would start out slow considering how severe your condition is. These baths don't dry out my skin. In fact the Epsom Salt actually makes my skin feel very soft with just the right amount of moisture. You would probably want to lower the amounts of these things until you know what works for you. These baths simply draw the toxins that are trapped in your skin. The hot water also draws out toxins and opens pores to be cleansed. I know you said that water seems to make things worse, but I still think this is worth a try. Perhaps your skin isn't as efficient at getting rid of toxins. The skin is the largest elimination organ we have and if it can't do that properly, I would expect things like acne. You can use the salts on your face as well, just use much less obviously. Don't splash your face with the bathtub solution, it would be too strong. I would fill the sink with some warm water, add probably 1-2 TBSP of Epsom and 1TBSP of dead sea salt, also 1TBSp of baking soda. Mix it to get the salts to dissolve and then lightly splash your face with it(maybe a couple of times), no rubbing. Rinse your face and then pat dry.
That is what has helped me now and in the past. Just so you know, dry skin can't heal itself properly. Your body is reacting to the dry skin by creating more sebum and this can cause problems. If lotion is too much, perhaps these salts or jojoba oil could benefit you. I noticed that my skin improved when I tried just focusing on the skin and not the pustules or acne, if that makes sense.