Flaking Scalp - But doesn't sound like dandruff

Hey everyone...
I'm in high school and the dandruff is killing me.
well, to be honest, its not bad, because unless you look really closely or i brush my hair out you can't tell. But just the fact that its there is what *****.

First of all, from all the research i've done, it doesn't sound like anything i've heard of before. Its not white. My scalp is never itchy. and it doesn't flake to the extent where i'm that guy with white powder all over his shoulders.

I'm gonna list some symptoms, and i would REALLY appreciate it if you guys could help out.

1) The flakes are brown-ish and scaly.
2) they don't really occur until I rub my scalp.
3) I may be wrong on this one but I feel like where ever they fall I get a pimple - to the point where i've noticed it not only on my face, but even on my arm.
4) I've tried HeadandShoulders, Nizoral, Selsun Blue - BUT ALL OF THEM SEEM TO MAKE IT WORSE. Right after the use of the shampoo, regardless of whether I use conditioner or not, the flakes are everywhere.

I have tried medicated shampoos, which make it worse, Apple Cider Vinegar, which just makes my hair smell and doesn't really cure it, and the doctors given me some Tari-Mometasone 0.1% hair lotion which holds off on the problem for a couple hours - but is not a permanent solution.

I was instructed to apply the medicated lotion to parts of my scalp twice a day - the family doctor said I had "lesions" - not quite sure what that means.  This seems to oil the scalp and thus prevent the dry flaking, but it doesn't last for very long.

My hair is very fine and straight when washed properly.  However, when its like that, I have flaking everywhere, so I choose to wash my hair minimally - because the "harder" it is, the less I experience flakes falling.  This however, doesn't feel very clean, and i'm desperate for a solution.

I live in a place which is cold and dry - Canada, obviously. But I feel like its the dryness of the climate which is causing the onset of the dandruff. I went to Mexico recently, and in the humidity my hair was doing beautifully.

To be completely honest, because of the excessive flaking after shampooing I have never stuck with it for more than a day or two - but the amount of white flakes falling everywhere prevents me from being in any social situation so its not possible for me to continue using the shampoo.

So at this point i'm not really sure what to do - because I don't even know exactly what i'm dealing with.

Any help would be GREATLY appreciated.