This is why your hair doesn't "grow"
Growing up I was always led to believe that black hair does not grow, or at least, does not grow as fast as other hair textures. I was deathly afraid of cutting my past-the-shoulders hair for fear that it would never grow back. I had friends in middle and high school who jumped on the Salt-N-Pepa asymmetrical cut fad (which, as it turns out, was a complete accident when a bad perm burned the hair off one side of Pepa's head, so she shaved it) and ended up having to permanently wear short hair when it was time to even it out. Or you just had the girls whose hair just always stayed short no matter what they did. I was considered "lucky" for having hair that went past my shoulders.
However, when I went natural 12 years ago, I found out this is a flat out lie. Or, at least, an incomplete truth. I cut my hair down to about 2", and within 6 months I had a full head of hair again, at least 6" worth. What I discovered is that it's not that black hair doesn't grow. It comes out of the root just fine, some faster than others of course. The problem lies in how fast it is breaking off.
Let's do some simple math here. If your hair grows 1" per month, but breaks off at a rate of 3/4" per month, your net hair growth is only 1/4". It's not the growth that's the issue; it's all the things you're doing to your hair to make growth counterproductive. All of the growth serums and scalp treatments in the world won't do a bit of good if the ends of your hair are breaking off at a rapid rate.
So what causes breakage? Damage. And what causes damage? Heat, chemicals, and physical stress. The very processes designed to make our hair "long and pretty" are damaging and destroying, causing split ends and breakage, which gives the appearance that our hair does not grow. Many women that you see with long, thick straight hair do not have perms, but rather press their hair so that they don't have the combination of both chemical and heat damage. What saved my hair when I was younger was the fact that my mother always did my perms using a mild relaxer, and I got touch ups every 8-12 weeks, not every 6 like my friends.
I think this myth is the root of the problem (no pun intended) when it comes to deciding how to transition from a perm to natural hair and the fear of the Big Chop. This myth has been ingrained into our heads so deeply that we believe that if we cut off our long hair, it won't grow back quickly and we'll be "bald headed" for years. However, once you stop doing all the things that cause damage in the first place (and probably the reason you're going natural anyway) you will have greater "net hair growth" as you have less breakage to counteract the growth that has been occurring all along.
So stop believing the myth that black hair does not grow, because it does, just like any other type of hair. If you cut the perm off, it can and will grow back longer and stronger than before, and quicker than you think.