How can I get a restraining order on my boyfriend's ex if I'm pregnant?

I am currently pregnant with my boyfriend's child. I am terrified of my boyfriend's ex girlfriend because after they broke up, she turned into a crackhead and went crazy. We have been dealing with many things with her for months and I am done with dealing with this. I want a restraining order on her. We live in Florida so I was wondering what I would have to do.