Cheesy Substance? Purple lower head? Smegma? HELP!?

Hey, I am 15 and recently I have been getting used to washing under my foreskin, even tho I had never even known you had to until recently, seems to be clean and normal on the higher head, but at the bottom of the head/ top of inner foreskin, there is this cheesy yellow substance on that bit of my inner foreskin and lower head, and note that I do not pull my foreskin all the way back so it gets trapped as I dont really like it and I am kind squeamish, so i pull it back till it is nearly over the head, and I discover this cheesy substance there on the lower parts of the head and even on that inner part of the foreskin, so I let water and soap run over it in the shower and have been for weeks, but nothing really changes, until I can get a little grip on the substance and peel it off, note that there is quite alot of it down there but I really dont like pulling my foreskin all the way back like they do in pornos. Also where there is that substance also that part of the head (near the bottom) it is a dark purple colour and goes all the way around the head of the penis, can somebody please explain to me what it is, and what I should do, because I am getting quite worried and I am also worried that if girls see it and freak out. Please somebody help me, I am 15, and I am a virgin, and I am not/never going to get circumsised! HELP