A lot of what I'm reading here tells me that there is enough here to work with to salvage your marriage and relationship.

As someone who is incredibly introverted, I can related to valuing your alone time. My brain/spirit/whatever never feels like it truly recharges to 100% unless I have time away from people, being around them, having to make small talk, etc. I was married to someone on the opposite end who needed to socialize and was extremely emotionally needy.

I can barely describe the euphoria in first months/year following my separation, waking up and proceeding through my entire day completely unbothered whenever I wanted. But I can tell you that the wanting and longing for companionship doesn't magically go away. You presumably courted, wooed, and married this woman because you're in the 99% of men who want to feel that companionship in some capacity. I would highly suggest trying to communicate that and build a schedule with your partner that meets your needs as well as hers, and that could/should include days in the month when it's understood that you're completely free to do your own thing.

It's not healthy for anyone to be attached at the hip. Both you and her need portions of your life that your own, with the space to enjoy your separate hobbies and friends, with little expectation of texting 24/7. That will sweeten the moments you do spend together, and even "recharge" you with the capacity to feel the romance you used to.

EDIT: Speaking of romance I read another comment from you commenting on how the romance/lust has seemed to fade. The good news there too is that there is a lot you can do to shake things up. Look up Ashleigh Renard on Instagram, who talks about "how to keep monogamy hot." Google sex games, experiment with new toys and positions. Make time for short weekend vacations and new experiences.

The second positive thing I'm seeing from this is that she doesn't seem surefire on having kids. I would communicate with her honestly about that. On the flip side, as someone who never cared for family functions or children, when my own was born I felt a love for them that I have never experienced for anything on this Earth. I'll also add that having one or 2 kids is not THAT bad. Your life doesn't end. Your hobbies don't end. Your friends don't magically go away. You don't become a boring "family guy" unless you chose to. It takes an added effort to balance all things, but the people that don't do that or either lazy or just extremely disadvantaged on the money/family support scale (and if you're a tech worker and have supportive parents and in-laws, that's not an issue for you).

All this to say, give this time to marinate. Maybe see a therapist for a few sessions and see if an unbiased third party can see your forest, even if all you can see are the trees. It's fun to wake up on Saturday morning unbothered and free to play video games all day, but it's going to be extremely painful to see the person you've loved for 5+ years slowly emotionally detach, see other people, etc.

EDIT: One more thing I would mention. I would also highly recommend booking an hour with a laywer and get them to give you a good understanding of your state's family law and court system. What of your property will be considered marital and separate? What are you still on the hook for as soon as you file? Do you live in a "equitable distribution" state in regards to martial property? When you get down the road into a separation and divorce process, your SO is going to get counseled by someone as well as her friends and family, and those late night pillow talks about what you would and wouldn't do to each other and go after financially if separated are null and void.