TLDR: Deeply questioning my wedding and not sure how to work on it and feel satisfied with my fiancé. Now I'm fearing saying I do when I think I don't.

What is the problem, and what do you think is the root of the issue? I'm 25 and have been deeply questioning my upcoming wedding in 3 months. My fiancé (30M) is wonderful, kind, hard working, with great character and RPW "captain" values. However, since we've been together, and especially since he popped the question, I've been feeling a sense of dread about the upcoming nuptials. Since the beginning of our relationship, I've wanted to feel a burning desire for him, but my feelings never fully turned into romance, as much as I wanted to believe they did. Despite this, I admire him and have a lot of fondness for him, everyone loves him and thinks we seem great together which is why the relationship has lasted as long as it has, he's just a great person and I love him, but not passionately. We get along great, never fight, and make great companions, but more often than not things feel excessively stagnant. I tried talking to him about specific things he and I could do differently to better equip us for a happy marriage, but he doesn't seem to be on the same page, understand what I am saying, or feel motived to change anything. Unfortunately, I'm fearing that I'm headed for a sad existence of a mediocre, melancholic, brother/sister type relationship, and he is completely unaware of this.

Here is a list to better organize my thoughts: -In every way possible I try to be the best woman for him. Keep in shape, dress femininely, cook for him, supportive, encourage him, etc. -I've never orgasmed with him. I feel so alone and disappointed, even having "the talk" about jazzing things up in and outside of the bedroom. -Having intellectual discussions and a curiosity about the world are important to me and he doesn't seem to care to explore these topics with me on a deep level. -I think about being single all the time to the point where I've developed crushes on others (never acted on them) -Planning the wedding has given me feelings of dread rather than happiness for the last 6 months. -Anytime I make an irreversible decision, like buying my dress I get scared of how final it is. There's a nagging thought of "what's wrong?" -Even if I felt completely sure about calling off the wedding I feel like I have to go through with it because of the embarrassment and hurting my fiancé.

How have you contributed/attempted to mitigate the problem? I've asked him directly how I can improve, what more can I bring to the relationship, etc. but he does not think that I should change anything. He genuinely seems happy/satisfied with our relationship. I said I didn't want to settle for a relationship where we come home, sit in a chair, pop a few beers, and turn on the TV. I told him I was frightened to marry someone who doesn't share the love of life in the same way. I explained that his passivity in the relationship has caused me to feel taken for granted. That it seems like I am sleepwalking through the relationship and living the same day over and over again. It doesn't seem like he consciously finds ways to make things happen, and when I ask specifically and lay out a plan, he doesn't follow through. Because of this, the excitement has waned (which is expected 5 years in) but I can't help but think the core components for romance just aren't in the cards for us. Or if it is a possibility, I'm not sure what I can do to infuse our relationship with happiness.

Are we completely doomed? As un-RPW as this sounds, am I just not ready to settle down? It seems ridiculous to be asking this since the goal of RPW is to find a committed, loving man (which he is), but is that enough?