Why wont my hair friggen grow!?!?!?

dude,ive been like taking care of my hair and trimming and leave-in conditioners and treatments and what not,but ive been doin this for a while and i dont see much difference!!i mean my hair is really healthy and shiny and soft.i have thick coarse hair.they say african american hair doesnt grow much.but im mexican.ha!so if anyone has any regimenns or crap i can put in my hair just to give it that extraa oomph!!please share!and also a good regimen for maintaining healthy locks&&hair growth!!!any information will be EXTREMELY appreciated!!thank yhou!!<3