If you are from New Zealand the Family Services Directory has a full list of all the help and support agencies throughout NZ.
If you really don't know where to find help, try a GP, they will be able to tell you about all the services and options available in your city.
Outside of NZ try Googling 'Depression help in your city' or 'Support groups for Depression' or 'Suicide Hotline in your city'.
Lifeline NZ - Toll Free: 0800 543 354
Youthline NZ - Toll Free: 0800 376 633