Dermatitis treatment?

Three years ago I was bullied in school and as a result I got into a bad habit of pulling out little strands of my hair by the follicle. I have now been left with a bald patch behind my ear and at the front of my hair. To hide this I straigthen my hair so its covers it, as I have naturally afro hair. I havent pulled out my hair in quite a while now but the hair has still not grown back and on the front patch only little strands have grown. I also suffer with burnt smelling hair from straigtening but even after I wash and condition my hair the smell doesnt go away. If I wash my hair and gont grease my scalp I suffer from dandruff and my hair is so weak it breaks easily. Is ther anything I can do to stop this.