Should I break up with my fiancé?

My fiancé and I have been together for six years. We own a house together and live together. But six months ago, I began having doubts about our long-term compatibility. I love discussing big issues: religion and politics. He can't stand it. I'm deeply spiritual; he's firmly agnostic. I crave affection; he doesn't. Recently, the physical intimacy has completely ended. We never touch. Ever. He's even mentioned twice that he's no longer attracted to me, but he's attracted to other people. He talks about marriage and stability and material comfort, but I wonder if he wants those things generally (with anyone), not necessarily with me specifically. More and more, I feel like we've become roommates or friends, instead of a couple. Breaking up would be messy. He's a great guy; we share the same friends; our lives are so intertwined. I don't want to mess up my life, but I'm so unhappy. Why isn't he? Is this the life he wants? Is this normal?

Wow... This is like my situation. First off do you honestly love him? Do you truly "want" it to work out? You've been in this for a good amount of time so you should know the answer. A side thought...is he cheating? Are you? Leaving that hopefully no one is but anyhow if you want to work it out and not be miserable then one of you needs to give in. It's kind of like a sacrifice for the relationship. I'm not talking about hurt or abuse but that one needs to put aside their...idk whining for a minute and cuddle, be intimate, get creative like its the first year all over again. I know it sucks sometimes be the person to do it but sometimes that's what significant others should and need to do at times. If it does get to the point where you have tried and tried, then maybe it is time to move on...? :/ In my situation I want more affection, sex, communication, fun, and definitely become stronger in my Christianity with her. Honestly at times I feel like giving up and feel completely miserable. I've said mean comments but it's cause I felt "sorry" for myself. Idk...I hope this helps.