Hair! Not the musical

I’m having my annual angst about my hair.  It’s thin, fine, turning grey and has a natural wave so that the moment it gets damp, it dissolves into wiry curls. It doesn’t respond well if I use too many products or heat on it so I am limited to styling options. I’m not vain but I think if fair to say that if there was one personal feature I could change, then it would be my hair.  I’d love to have thick lustrous locks that take very little managing and retain their styling for slightly longer than half an hour