There are many places that you can access support from others who have walked or are walking a similar path to you. Here are some places to start;
Carer Gateway: This is a portal to a range of information for unpaid family carers. It does not matter if you have a carer payment from centrelink or not, just that you identify as someone who is caring for a family member who has a recognised disability or long term illness. Resources include free carer counselling; information about financial assistance and networks and opportunities that may be available.
Little Dreamers has a range of supports for siblings of children who have special needs.
Better access to mental health programs can be accessed with a mental health plan from your GP - just ask them :).
Facebook: search Facebook for your local relevant community support group to connect with other parents in your area that may be experiencing similar things as you.
Autism Queensland currently facilitates existing Helping Children with Autism funding and have a range of services in Queensland. If you are in a different state, or are outside Australia then google the Autism organisation in your local community.
Your local NDIS partner can also assist you to find local supports within your community. Click here to view the contact details for NDIS and find out who your local NDIS partner is.