I'm just curious, I'm worried my ex will try and take me to court and try get cutody for our son, He has not seen him since christmas. He has not asked to see him. He has a 5 year old daughter(wit his other ex) and he has not tried to get cutody of her or to even see her. All his centerlink money goes on alcohol and to the club and pokies. I fear my sons like around him and his father, he has not supported either of us, I pay for everything, which I'm fine about, I pay for my sons food, clothes, shelter, transport, medical bills, toys everything, he however does not, he has tried to hit me before. I would defend myself and try and grab our son who would be asleep, and I'd push him out of the way to get my son so I knew he was safe. He would still try and through a punch at me, he has got a record for violence. There is so much more about him and his family that makes my son not safe around them. I fear my sons life, for safety, being exposed to drugs and alcohol, domestic violence, neglect. There's so much more I could go on with.
But if there is anyone at all that could help me, in giving advice in what would happen if he took me to court, what I should expect whether I will get full custody or I will have to share, any true information would help. As I am so terrified, and fear my sons life I can't even walk through town, because I'm scared him or one of his family members will come and start hitting me and take my son.

First to get custody he would need to prove you were not a good parent, maybe even unfit.
Next he would need to prove he would be a better parent.

You would show evidence, like police reports of all the times you called them when he got physical with you. Proof from police reports and arrest records of his drug use. And so on.

I don't have "Proof".
Ive been waay to scared to talk to anyone, I left him just over a month ago, and I know what he is capable of. And I've only just found the confidence to go see someone tomorrow about a no contact order.
I know I have to do it because it's for my son, my family and myself's safety. But am extremely scared of what he will do. No one ever sees behind the scenes, so its my word against his, I don't have evidence because of how violent he is like I said I've never been able to tell anyone .

This is what is going to happen. If he goes to court, you will have to get police reports, character witnesses, etc to his behavior. He will have to do the same with you. The judge will then try to figure out who is telling the truth and decide what is in the best interests of the child.

It might be taking the child away from both of you. You had sex with this man and lived with him up until very recently. You never reported any of the abuses. This will work against you. If you leave the state without his permission, you could be brought back or the child could.

I strongly suggest you seek the help of a support group for abused women. They can help you with legal advice, develop a strategy and help you build yourself esteem.