Have we waited too long?

My fiance and I have been together 7 years, engaged for 4. Is that too long of an engagement? We don't plan on getting married until 2012-2013, making us together for 8 years engaged for 5. A lot of people freak out about the fact we haven't gotten married yet. We can't get married, because we can't afford health insurance and we're both getting our Masters, so we stay on our parents health insurance as long as we can. Some people might think this is a rational normal thing to do, but we have made a promise to ourselves that we would save ourselves for marriage so we're not intimate in THAT way, which also tends to take our family and friends aback. Have we waited too long and have moved into the friend zone? We don't believe in kissing or anything before marriage and I'm just now wondering if we kinda shot ourselves in the foot for putting it off so long and making a promise of chastity to ourselves. I love him, I find myself attracted to him, but the thought of sex (not with him alone, with ANYONE) is nauseating to me. I feel as though now my family and friends are gonna know we're having sex and I don't want anyone to ever think I do that, because I see it as something dirty (not because of religious reasons). What is wrong with me? Has waiting turned me into a prude? I used to want to do it all the time, and my fiance still wants to do it. I just don't feel the way about sex I used to. It repulses me now. I feel as though another person invading your body is not sensual or romantic it is beastly and gross. I'm just overall confused about us in general.