Baby almost here, freaking out

I'm about 3 weeks away from my due date and I feel guilty because when people ask me if I'm so ready at this point, I say yes, but I'm really not. I'm so scared to give birth. And I'm even more afraid of being a mother. I've never been the "motherly" type, never babysat, I've never even changed a diaper! I have everything I need for the baby and a very supportive husband, but I just don't feel ready. I know my life will never be the same and I'm freaking out. I feel like I'm not as excited as I should be like all of these other moms who can't wait to meet their babies. I feel so guilty. What is wrong with me?!