Hi Wobbie
I don't live in Melbourne- I'm actually in rural NSW. I found the public mental health system largely unhelpful to me- the people I did see who were qualified to help were good, but they were not people I could be assigned to see regularly. The people I was assigned to, lets say if they'd picked up on my avoidant and autism traits at the time, things may well look different to what they do now. I have been "in the system" since I was 16 (I'm now 33).
I have been able to access help with a clinical psychologist in a private practice, receiving a capped number of sessions (10) through Medicare (with referral from your GP). If I make the appointments fortnightly, it gets me a bit further through the year, and then my therapist does subsided sessions for the rest of the year because I'm on a disabled pension. His approach has been most helpful. Would recommend looking for someone with an interest in PD's and someone who can do CBT with you. CBT can be highly effective with AvPD, and it is actually one of the most treatable PD's. Would also ask your GP if they can recommend someone you can be referred to.
I get struggling through a job you're not suited to- I'm trying to find myself another one at the moment. I've signed up with a job agency who only deal with people with a disability- so going in there and saying "I just can't do this whole retail/hospitality thing I'm doing now", they get it. Might be worth looking into?