Ready to leave but not sure if I can

I have decided to leave my husband for my children's well being. I love him but I'm not in love with him and he is verbally and mentally abusive to our son. I know that leaving is the right choice. But I'm so scared. I'm scared to be a single mom and rely on my own small income. I'm terrified for him to have the children when I'm not around to protect them. He knows I'm getting ready to file and I asked him if he would agree to only having the children every other weekend and I have them the rest of the time so he wouldn't get 50% custody and he said yes. But what if the court still orders 50%? I plan on getting a lawyer so that I make sure I do it all right. I just want whats best for my kids.