Woah. Wait up a second. First, as others have said, call the police, don't cast a spell.
And later, after you do that, you can CONSIDER a spell. But, casting a spell requires a lot of visualization, and I don't think you want to focus on that moment.
Also, while whoever raped you deserves terrible things to happen to him, you do not need to be the one to deal out that punishment. If you are new to spells, something like that could backfire and you could get even more hurt.
I would suggest trying to find healing spells for yourself. And protection spells. They are a little easier, and aren't as likely to backfire. I would also suggest that you study witchcraft, wicca, or paganism some so you can get a better grasp on what you're dealing with. You can't just dive head first into this stuff.