If you need to talk to someone, there are a range of mental health organisations that provide professional phone and online counselling 24/7, free of charge.
They also provide lots of online resources and can put you in touch with additional help and services:
Lifeline on 13 11 14
beyondblue on 1300 224 636
MensLine Australia on 1300 789 978
Suicide Call Back Service on 1300 659 467
Kids Helpline on 1800 551 800
Headspace on 1800 650 890
QLife on 1800 184 527
For further resources on climate anxiety:
ReachOut Australia
Psychology For a Safe Climate
Climate Council