Hi there
Just wanted to add my support, and sympathise with you, we add the same with my mother 3 years ago when we first tried to move and now it is about to happen - honestly I'm too scared to tell her yet, despite us moving in january!!
Just know that this is your life and that they love you so much they don't want you to change or anything to be different. I know how hard it is, but you just have to keep telling yourself that your immediate family are the ones moving to NZ and that they are the most important right now.
Everyone will come around I know it (keep repeating it might just come true). Take a deep breath and try to forget anything that is hurtful to you - it's just their hurt coming out.
Take care and much love