I collaborate! Our comic started as a duo thing between my friend and I--she was the stronger writer but could kind of draw, and I was the opposite. We RPed most of the first draft and then begun editing ever since.
Nowadays we're a team of five. My fiance is the editor and researcher--honestly, the world wouldn't be nearly as fleshed out as it is without him, and he helps keeps things consistent. We also have an art assistant and a background artist.
Us main three all have creative control in places, and honestly I really enjoy it. It was hard at first to "let go" of my ideas in the beginning, but honestly it's just like any other professional relationship: you don't take things personally, you compromise, and you do what's ultimately best for the product and not your ego.
Honestly, this sounds really stressful! Something a lot of creatives do is attach themselves and their self worth to the work, and I wonder if that's what's happening here? I think it would definitely be beneficial to separate yourself from what you create, at least a little bit, so you can look at it objectively and not see it so gravely when someone gives feedback you don't agree with.
While it's fine to not ultimately take critique from someone else, I think it's valuable to try and dissect why they are giving it and what part of their reading experience is getting snagged. You can discard a critique easily if their hang up is about a theme you're not trying to tackle, but if for example you're trying to write a mystery and they're telling you you're being to blunt with the information, it's important to reexamine that because you're not executing the ideas properly.
There were definitely times where I didn't want to budge on some details in our story because I felt it was "out of character" or "important" to the story, but ultimately I realized that my characters are still flexible works of fiction and maybe that important detail can be handled in a better way.
Being objective with your ideas and allowing yourself enough detachment to examine those core parts with honesty doesn't decrease your passion, investment, or--as you put it--"primal sense" of the work. It allows you to improve on and elevate your vision for the story!