My hair got damaged some 4 years ago after a botched job at Toni and Guy. They were going through the stages of taking me from dark brown to ashy and the bleach was left on my hair too long! 
Cue a few months with very short (broken) hair layers on top, and the rest shoulder length, and lots of people asking if I've gone for the "Rachel look" (and even though it's retro I don't think it's back on trend just yet)!
Anyway last year after waiting aaages for it to grow and not using any permanent colour or (heaven forbid) bleach, I ended up getting extensions (Brazilian knots, which are completely natural with no bonds or glue, all they do is knot them in naturally) as I couldn't bear waiting for my hair to be long again any longer. They've been great!
However, whenever I get my knots re-done and see my natural hair, it seems to either not be growing at all, or getting shorter! 
my hairdresser says it is getting healthier and is no longer dry thanks to my hard work looking after it, but I don't feel like it's growing and I originally envisaged getting the extensions to tide me over whilst my real hair grew long again, but now I'm wondering if I'll ever have long natural hair again.
I'm late 30's - does hair stop growing or an I just being silly? I have a little trim each time I get the knots replaced so that it stays healthy. I use loads of conditioning treatments and no sulphates should etc. What else can I do??
To compound matters, I have been dying my roots using semi-perm root touch up to cover a few greys and now it's getting darker so I'd love to lighten it all by a level or so, but daren't in case that sets me back a few years!!
Can anyone advise me on this please? Thank you xx