Hair Dye Answers

As you have read in the question, my hair seems to be in terrible shape. I do not understand why because the only “trauma” I occasionally put my hair through is dyeing, which I do about once every three months. Other than that, I only finger comb my hair, I wash it in room temperature water, & use somewhat pricey shampoos (Paul Mitchell Smoothing, this organic minty tea tree stuff, John Freida Brilliant Brunette, & occasionally Garnier Fructis Shine Burst -I switch between these about every 2 or 3 showers.) I also use the Paul Mitchell smoothing serum. I NEVER straighten, blow-dry, or curl my hair. I bought a hot oil treatment which was also to no avail. I get my hair cut about every 3 months, & I use my towel very minimally when drying so as not to further damage my hair.Yesterday I bought a vitamin supplement called Biotin at 1000mcg (I only know that this means ‘high potency’ because it says so on the bottle). After all the crap I’ve tried, I doubt it’ll work though.