Cute but not sexy.

I was raised in a super religious home, my dads a preacher and I went to church every Sunday. I was raised to wait until marriage for sex, but I started a serious relationship when I was barely 17 and gave it to him- we're still together now almost a year later. The problem is, I feel cute, and I mention my religious past because I believe it does have some impact on how I feel in bed. I'm super confident with my looks and I know I'm good looking but I just don't FEEL sexy or really sexually appealing. I have that little kid look with big, innocent eyes, though people often guess I'm in my mid 20s. This feeling is affecting sex with my boyfriend and I don't know how to help myself!! I know there are other girls out there who feel or have felt this way. What did you do to boost your sex confidence?