Are these symptoms of any type of skin cancer?

The past few years I've developed little bumps on my head.. Sometimes itchy, or red, or bleeding, and hurt all the time. I went to the doctor she didn't help at al she said I had dandruf(sp) and gave me shampoo. That didn't help it only made it worse. Then I thought I was developing psoriases(sp) but I googled and researched that and I'm thinking that's not what I have. I'm a little nervous and I'd like to know about this because they hurt and bleed and its so aggravating. I'm also diabetic I don't know if that has anything to do with it? And I also just started thyroid pills I heard that was suppose to fix dry skin but it didn't. I have done all I can do I've tried all the different shampoos and creams and nothings worked.