There are a great number of wonderfully caring individuals out there who are great to be friends with and have in your life but would not be a good choice of a spouse simply because they don’t share your values. I personally know several gentleman who are great to talk to, vent to, share a meal with (all in the presence of my husband, of course

), etc. But I couldn’t see myself married to any of them because they do not share my values. They think premarital sex and contraception are ok. That is something that would not work for me because I will not compromise my adherence to the Church’s teachings.
What are your views on NFP? Do you wish to practice it once married? If so, I will warn you that it is not easy. Although a woman’s true fertile phase is very short, most systems of NFP that carry a 99% effectiveness rating usually require abstinence that extends beyond the true fertile window just to be safe. If you wish to use NFP to space children after the birth of a baby, it becomes even more of a challenge. While your hormones are readjusting post partum, your body will throw out fertile signals almost continuously and you are not sure whether you are truly fertile or not, so you will just have to abstain for months - yes, months - at a time. My husband and I were lucky if we had two days once every two months to be intimate after our baby was born. Will your fiancé be able to handle this?
I am incredibly blessed with a husband who is faithful to all of the Church’s teachings, believes in them, and wants to follow them because he agrees with them. He is one of the most unselfish people I know, always putting me and our child before himself. He never demands sex of me, even in marriage. During the long fertile phases, he finds other ways to be close to me and adheres to the abstinence without complaining.
Even if you don’t agree with/wish to practice NFP, there will inevitably be times when sex is not possible. After you have a child, the doctors will require that you abstain for at least 6 - 8 weeks after the baby is born so you can heal. How would your fiancé handle this? How would your fiancé handle things if you, God forbid, acquired a medical problem that required total abstinence from sex for an indefinite period of time?
I’m sure he would stay true to you no matter what - that is, he would not divorce you. I’m sure he wouldn’t divorce you under and circumstances. That doesn’t mean your marriage will not be, well frankly, a living hell. As HoosierDaddy pointed out, there are many threads on here about people who are miserable in their marriages because their spouse does not share their beliefs and turns to things such s masturbation and pornography, making them feel humiliated and degraded. My parents stayed true to each other no matter what, but their marriage was a living hell due to certain issues (not sexual, but serious nonetheless). Not to mention it was a living hell for me, the child.
You say he is a wonderfully caring person, and I believe you. I’m sure he is a great person who is kind, thoughtful, generous, caring, and wonderful. The question is not whether he is a great person. The question is ARE YOU COMPATIBLE ENOUGH TO BE HUSBAND AND WIFE?