not sure where you are located but in QLD there is Carers QLD that offer free counselling and support for carers (i am a member as my husband has an acquired brain injury).
i'm pretty sure the individual states should have their own government funded versions of these.
i cant even begin to imagine what you are going through, but i can say the staff at carers qld have been amazingly supportive since my husband got his ABI. sometimes it's just good to let it all out and have a cry, complain, etc to someone.
Best of luck