Had your problem. A few years ago my hair was uniformly long and I was disappointed that my hair went from very curly/spirally 3b/c hair to 3a/3b waves and curls. So I had it cut with a bunch of short layers starting from around the crown and kept some of the length in back. Much better!
Just fyi: henna has been known to relax curl patterns for quite a few people, especially repeated henna treatments.