I have a problem with black textured hair. It's full on top and weak at back. Can it grow all around? Thanks.

My black-textured hair has always grown in layers. For years I've never had my hair grow past my neck. Even after having gotten "Jeri curls" it still won't grow. I've used so-called "miracle gro" product after "miracle gro" product and taken hair vitamins but still to no avail! I shampoo my hair at least twice a week, and sleep with a satin bonnet-like cap that I purchase from beauty supply stores nightly to prevent breakage, but still my hair grows full on the top, and weak at back. The lady that does my hair, says that I should refrain from getting a curl for a while, and let my hair grow out in a "natural" to give my hair a rest from all the chemicals. I last had my hair done in November of 2006, and still I haven't noticed any significant growth. I even have a little "bald spot" at the top of my scalp in back that really is bothering me! She said that I may be in the early stages of "male pattern baldness" which I don't agree with because I see hair growing in that area.