I (M34) have been with my long term partner (F37) for 10 years, and we have lived together for 8 of those in a joint mortgage house. This is my first serious long term relationship. The intimacy of the relationship disappeared very quickly after moving in, so for all that time it feels like we have been living as roommates, albeit getting on great, going on long trips and vacations across the world, but in my eyes more as great friends, not life partners.
A friend of mine asked me recently why on earth I hadn't proposed, and I think that is one of the starting points for why my mental state has started unravelling to the point that I'm questioning if this is what I want at all. When she leaves to go on trips with her friends, I look forward to living alone for a week like a schoolkid waiting for the summer holidays – I'm so excited to get back to living on my own on my own schedule (I'm a night owl). We don't share hobbies, so all my many nerdy and sports interests have nowhere to go, which was never a problem before but it's almost as if my eyes have been opened to the fact all of a sudden and I have no idea why I'd stay with someone who doesn't share any of my passions. I go to music shows alone or with other friends, never with her, I play at local gaming nights each week alone, because she has no interest.
However I woke up this morning thinking about calling it quits and burst into tears with no idea what decision to make. If we can live happily together for 9 years despite the lack of shared interest, will I ever find someone like this again? Is this just naturally what happens with couples or do most maintain that intimacy over time? What happens to my beloved house that I've invested tens of thousands into improving, and will I end up living alone in a tiny box apartment somewhere instead? Is it telling that my concerns are more about money and belongings than whether or not I'll miss being with her?
At this point I do not feel comfortable even discussing these things with her, which in the back of my head means this is over. But I have no idea what life looks like without this and it terrifies me.
TL;DR: Been together for 10 years and I am terrified of leaving despite having little to nothing in common and no intimacy. I have no idea what life looks like beyond what I have now.