But what these recent thoughts/experiences have shown me is that I haven’t been feeding a very important part of my soul - the part of my soul that misses these certain positive emotions of connection and understanding and love and intimacy. I didn’t do anything drastic. I started a conversation with my wife that went “Our relationship is stale. We’re living parallel lives. We don’t understand each other. I am lonely in this marriage. This can’t continue. What now?” Can I find intimacy and connection outside of my marriage? Absolutely. I work very hard on my friendships, actually. But I also want it IN my marriage. If that’s not possible, fine, let’s call it a friendship or a co-parenting relationship or something else, but it’s not a marriage, not to me anyway. These are difficult conversations to have, yes, and they are consciously difficult, but NOT having the conversation was also difficult - sub- or unconciously difficult. I’m for truth and openness and, yes, courage to bring these things to the light so open, honest, conscious decisions can be made. Call me crazy, but I don’t want to just survive any more. I want to live, and love.
Oh, I well remember when I was at similar fork in the road. However, my ultimatum was more along the lines of "If we don't start having regular sex, regular "date" nights, and working on projects together, I am outta here." Putting aside the issue of whether these sort of ultimatums towards difficult conversations, resolution, or date in divorce court "work"*, what I might suggest would be that it is unlikely that you are going to get what you want in contract renegotiations if you don't describe it more concretely. We can really only know or interact with other people through their behaviors inclusive of conversations. So, what are the sorts of scenes you imagine happening in a relationship that includes more of what you mean when you use the word "intimacy?"
I couldn't decide whether to post this bit on your thread or Gravy Train's. Ten years after I was in the phase you are in and less than 6 months after the end of my second briefer "marriage", I was on a second date with an attractive man of the sort I usually date. We were walking around downtown Detroit after dark and he was telling me an amusing story about working there in the late 70s. I was getting a bit sleepy, because my bedtime is usually before 9 PM, and I was distracted by my own thoughts, so I unconsciously put my hand out as if I expected him to take hold of it. Later he texted that he thought it was "sweet" that I made that gesture, and only then did I realize that I had made the intimate gesture, and I was a bit freaked out by that realization. My point being that there are these strands running through you, some inherent and some gained through experience interacting with others in various forms and phases of relationship, and you won't necessarily know what belongs to you "This is how I am 7 years into a relationship." or "This is how I am when I fight with an ENTP" or, even, "This is how I am walking through the city after dark with a man I momentarily forgot wasn't my husband." or what doesn't until you've visited that place more than once.
The doldrums are absolutely to be expected in any long term relationship, and mid-life crisis is absolutely to be expected in any human experiencing hormonal decline (oddly doesn't seem to happen to lifelong single men until their mothers die) in currently infertile relationship, but it is also true that more or less than that may be going wrong or going on in your marriage. It really is difficult for outsiders to judge, especially given only the written version of one half of the story.
Second question would be if you are truly committed to getting down and dirty in the crucible trying to achieve a greater state of intimacy/passion in your marriage, are you ready to do your half of the work in terms of listening to what your wife has to say on how you may be exhibiting behaviors that are making it difficult for her to achieve or desire intimacy with you? For example, one of the things my ex threw out at me (after breaking the edge off of a counter top, because he was so p*ssed" was "You are too nerdy to f*ck."
*Hindsight being 20/20, I3 years down the road from my years of marital dissolution, I would say that I wound up with the right result even though my method was half dysfunctional.