I can emphasize and relate. Unfortunately.
My wife of 10 years died of something called ADEM. "Acute disseminated encephalomyelitis". I'll save you the search, it means something (often immune system) strips the Myelin off the nerves in the brain. No Myelin, no proper electrical conduction. In my wife's case it was described as "fulminant", which means "severe and sudden onset". No kidding. She went from standing and talking to bed-ridden and not knowing who I am in 4 days. 3 days after she was "solement", meaning she wouldn't wake up fully. This is commonly described as "being in a coma". About a month and a half later I stopped supporting treatment, just like you did. I, she, were "lucky" (heh) that she didn't survive much longer and died just 3 days after.
I remember the doctors explaining the MRI (took a long while to get a sympathetic neurologist that actually sat and explained to me what's going on), the hopelessness, the decision to pull support and accept whatever happens next. I remember telling the hospital staff "just make her comfortable", though I didn't believe she was still there. Her brain was too far gone.
That decision was the hardest I had to make in my life. "yeah yeah" people might say (not you though, Lars, you know). But no. It was the hardest. To give up on the person that made your life whole. To know there will never be a replacement. Hoping (sorry, not a religious person, I don't really pray. I did try to make lots of deals with god during that time though) that things will get better, then just easier, then finally just end quickly.
Brain diseases are horrible. They frighten me beyond anything else in the world. You see your person change, disappear. That made me not believe in after life, souls, etc. What existence can there be after if you see memories disappear all at once, basic abilities like talking, moving, eating. Maybe there is something, but it's not the person anymore. That was the brain, the memories, the learned behavior and experiences they had in their lives. And when it's gone, it's gone.
I know what descending to that dark valley is like. What walking through it is like. I hope you can come back up towards the light. Eventually. Maybe.
One bit of practical advice: Reach out to psychologists (talk therapy) and to psychotherapists (psychoactive medicine). It's not a shame, it's a strength. Your brain undergoes significant changes and things get out of balance. Talking, pills - they both help. Today's psychiatric medicines are much more advanced and targeted than even 10 years ago, not to mention Hollywood's depictions. "But I'm afraid it'll change me, it won't be me anymore!" - sure, but is being you that great? You can comment here and I can share my own prescribed cocktail to your blog email.
Be strong. The sun will come back up. It won't be as bright or as warm, but it won't be dark forever.