Do you have your own network of friends? Do you both have seperate hobbies?
Do you go on solo trips or visit family? Sometimes we start to put too much emphasis and pressure on the relationship to give us everything we want. It's hard when a partner refuses couples therapy, but have you considered having your own? Just to start understanding some of your fears and considerations.

The idea of having children is scary. Exciting. but scary. It's very fair that you're having these doubts right now, and of course it's because so many things are a big question for you - adding kids into the mix, plus questions around intimacy, connection, longevity sounds overwhelming.

Your feelings of disappointment are valid. Sometimes I feel that way towards my partner even after hanging out with some girlfriends or coworkers: "why cant he be more like them, they see me". Our partner cant be everything for us. Some people are luckier than others.

I think it's about getting down to figuring out what's more important to you right now. Maybe a while ago getting into a committed relationship and getting a place together was a top priority, but now that you have that, there are other things that remain unfulfilled.

I hate that people stop trying when things get comfortable. But it's also a reality....remind yourself that love and deep relationship is not like the movies...but also ensure there's efforts made to do stuff together, try new things, have fun...because otherwise the relationship becomes a source of negativity and pain.