What is the crusty yellowish stuff around my nipples? Sign of breast or skin cancer?

This is a completely serious question, and I don't want any cheeky answers. I'm scared. For several years now I will have this gross yellowish-white crusty junk on and around my nipples. They will also hurt, maybe sting is a better adjective. It's not all the time, just sometimes. I read that it wasn't so worry-some if you're pregnant and close to the end. I am a female, but I am not now, nor have I ever been pregnant. I'm wondering if it could be a sign of breast or skin cancer. I heard once that some "draining" could be a sign of breast cancer, but I don't feel any lumps. I do have some other minor signs of skin cancer: I am Irish, lighter complected, blond hair, and I have a million and one moles all over, some of them are kind of shaped like a fish (on my back... I can't see it). My legs look like I have goose bumps all the time and I have had some random cuts in a circular shape of which I have no idea how they got there! And mostly, my skin is quite itchy and sometimes I feel like I'm being "pinched" for lack of better word on my back in the spot of a mole or near a mole. I have a dermatology appointment in January, but I'm a little worried. Please no cheeky answers! Thank you!
Nervous aka PDBHDK