Hair Loss / Scalp pain

Hi, I have been experienced pretty heavy hair loss and scalp pain to varying degrees for the past 8 years. My hair used to be thick, shiny, and healthy until I turned about 16 years old at which point it started falling out, became more course, and darker in color.
At the early onset of symptoms, the pain would be almost unbearable. My scalp was very itchy, sore, red and generally irritated. I couldn't comb it without cringing and i definitely couldn't run my hands through it. I couldn't touch my head without pain. In the years following this the pain has subsided dramtically, I can only assume because there's alot less hair on my head to irritate the scalp. I've been to three different dermatologists who were all extremely unhelpful. A scalp biopsy turned up nothing. Weird tranqulizer pain medication did not help. A multitude of shampoos did not help.
I am 24 now and while i still have pretty decent scalp coverage, it is merely a fraction of what it once was. No one in my family is bald. The thinning is all over, not concentrated in any one area. I am a relatively healthy male. 5'10', 165lbs. No major medical issues. I am a fatigued alot of the time. The pain is the worst when I wear hats or don't wash my hair for a couple days. At which point my scalp gets very oily. I have recently thought it might be a hormone problem as I see I share some symptoms with hypothyroidism and my father was recently diagnosed with that condition. However, my blood test from two years ago points to normal thyroid function. My hair has been graying also since 16, which seems normal because my parents are both gray.
Starting to lose hair at 16 was pretty upsetting to me, and my self-esteem has been affected significantly.