Pain To My Scalp, Only On Left Side; Is Very

Pain to my scalp, only on left side; is very tender and does not go away; is mostly tender to the touch and when brushing my hair. Pain has been constant but mostly annoying and has been present a couple of weeks. There have been no injuries or recent health changes. I am type 2 diabetic, not on insulin with my last A1C at 6.6 Also being treated for high blood pressure and had triple bypass heart surgery nearly 10 years ago..