unremovable hairspray residue ... HELP!!!

recently i`ve noticed that some of my hair is turning white. Im only 23 so its not possible(for me at least). my hair is black and somewhat thick. i use hairspray everyday. my hair is parted in the middle, shaved sides and bangs. ive noticed alot of hairs are turning white. but not fully white, the tips and roots are still black, but the middle is white. so i tried scraping the white stuff off and it comes off, but with alot of work and my hair starts to curl because i have to scrape so hard. i scrape this flaky stuff off which resembles hairspray residue. but i take a shower and wash my hair everyday. i`ve changed hairspray brands since then. i used some thermasilk brand before and im not sure why i got residue recently. how can i get rid of the residue? i`ve had the residue on my hair for about 3wks now and its getting worse. what products can i use that are available from the local pharmacy? thanks.