Four,
I'd suggest contacting the Rape Crisis Center or your local Women's Shelter. Sadly, sexual violence in abusive relationships is very common. Often the victims don't even think of it as rape until later--they just know they were scared and that it wasn't right.
You don't have to file any criminal charges to get help (though if you want to, that can be done, too). These groups can refer you to assistance for survivors of sexual violence and domestic violence, where you can have a safe place to work out your feelings and start to heal from this.
I'm so very sorry that it happened to you--it's a horrible violation of your dignity as a human being, not to mention a spouse/partner.