You really need to talk to him about this, not us. It's one thing to prefer you the way he met you, but it's another to tear you down and make you feel ugly for having curly hair. That's the way the hair grows out of your head and it's not changing anytime soon. You need to explain to him how awful it makes you feel and ask him to stop coming on so strongly about it. You're dedicating your life to this guy, and if he can't handle one change, what happens when you put on weight? Or start going grey? Or if you want to dye your hair? If he doesn't stop going on about your hair after you talk to him, I would seriously rethink spending the rest of your life with this guy.