My hair is about an inch past my bra line, and it won't get any longer. I've been trying to get it to my waist for years, but it just won't grow anymore. even if I get it trimmed it grows back to the same length and stops. and it's not like my hair is really damaged. I use no heat products on my hair. I air dry it and wash in cold water. I've even started taking vitamins. is there any way to get it to grow? or is it just going to get that long and that's it?