Imagine if God didn't forgive that Heaven would be empty. What your mother must do now is forgive you, tis one of the commandments!
God is merciful, he instructs us to be so. I'm not Christian. If your faith is important to you, don't let him, your mother or their trying to make you feel guilty ruin your faith.
God doesn't have a big master plan and control over everything and everyone. Poeple sin because they can. People forgive because they want to. Why would this god set you up and test you, or stand back and allow it.....he doesn't because he doesn't have absolute power. What you can have is faith, don't let them make you feel guilty whilst also telling you any bollocks about god's will.
If it were god's will that husband's abuse their wives, if it were god's will to test you and make you suffer, if God had absolute power to do this, how could you have sinned? Your husband made his own choices.
We can only feel guilty for choices we freely make. Your husband chose to abuse. You simply did what any living thing would do, save yourself. You have nothing to feel guilty for. You saved yourself and your children. That was not just a choice but an absolute necessity.