ASD support

My son is 12, he was diagnosed at the end of last year as ASD level 2. The first paed we saw at the age of 8 (rural waiting lists 3 yrs) told me my son was fine and I was over bearing. Perhaps I was feeding him way too much information but the reports from every single school or daycare he attended, backed up every single word I was saying.
Obviously it’s led to a massive lapse in diagnosis. I tried my hardest to learn as much as I could and configure home life around his needs but education has ALWAYS been an issue due to the lack of support available due to the lack of diagnosis.
We are in the web of the ndis process but it’s moving really slow. We are in crisis but. My son has been displaying violent behaviour, both with myself and at school. There has been a lot of bullying but obviously there is never an excuse for violence. He’s been taking off. Tonight was the third time I had to call the police because he took off. This time, it was from school. He got into a fight at lunch and punched a student. He was already on a very serious behaviour warning and knew this incident will probably lead to expulsion, so he ran. The school called me at 1:30 to tell me he had taken off and they lost sight of him. I got straight in the car and drove the streets for hours. Police were involved, if I hadn’t of found him when I did, they would of issued a media release.
Thankfully I’d come home to meet my dad to help search. As I drove off, he came around the corner of our street (7:30pm), my poor baby was disheveled, no shoes and confused. He’s not sure how he lost his shoes but he spent that entire time walking. His feet were all wrinkled from being wet and even the police couldn’t figure out exactly where he went or how far he made it. I’m not pushing it tonight, he’s obviously exhausted and just needs to wind down and rest but he’s either bare faced lying or he genuinely has issues knowing what happened tonight.
Obviously before anything else, we’re going straight to our gp who is really supportive and understanding of our issues and I’ll be getting his advice on what our next best step is.
I feel so lost, I don’t know how to deal with this. I’m trying my hardest. I’m trying to meet this with open discussion but I’m also a single parent with zero input from his father (no contact, fathers choice for over 7 years, drug addict that just got out of jail) and minimal input from family and friends. I have two boys and I feel like my son (who is the oldest) needs guidance that I’m failing to give.
What would you do in my shoes?
Does anyone know of anyone I can reach out to in the Gold Coast region. Right now I’m feeling desperate and willing to try ANYTHING. I’m also looking for education options that will suit his needs. At this stage, my plan is to homeschool until we find something suitable and he’s had enough time to adjust to therapies.
Tia x