I'm so sorry all this happened. Let me assure you that your children probably left the circumstances that happened, not you.
My advice would be to go to Centrelink and lie about being single, find three trusted friends/family to back you up. Save all payments, a new bank account, after three months apply for an advance payment and you will have enough to run away, go to the state your kids are in, live in a tent ($30 at Kmart) struggle for a while, get a job and find your feet. You're used to a camper, plus you will be free. Freedom knows no consequence.