Girlfriend and I living together with our son. What do I do?

Forget what Aureala is saying. I understand that you've messed up and look- God does, too. Some people stray away and come back to God during the toughest times. That's what he's there for. He loves when his children come back home. Remember the prodigal son? The lost sheep? The lost coin? All of those parables show that no matter what you've done, God is waiting with open arms. Just show him that you will be the best dad ever for your son. You have been blessed with his gift of your son's life. Let God, your girlfriend, and your son see how grateful you are. I love that you're trying to fix things between you and God. I hope that everything will work out for you and your family. :)