Fantastic piece. I agree with you 110%. I have found when I started to write, that I get into a zone "and" it just happens.
I am done with writing and I am like where did that time go. Poof. I wrote an unpublished piece on some exotic and erotic and kinky sex, and it was in a truck ride hauling horses. My partner looked at me and said where did you go for the last 2 hours.
She was like your hands were flying and then you slammed it shut, and closed your eyes.
Then I came back.
I believe the best writing (albeit grammatically may suck) comes when you connect your heart and mind to the pen/keyboard.
One gets into a zone like an idiot savante. Kramer from Seinfeld on Seinfelds "Comedians driving in cars getting coffee" stated he played with a person that beat him in 2 minutes and then in less time, while he was rated above a 2100 in chess play (master like level).
Writers get in that same space IMO, and it is draining on the soul. To fix or repair from that loneliness will usually require alcohol and/or drugs, because the need to connect or reconnect is deeply needed. The problem is the people that you normally connect with are like WTF ... you ignored me asshole/cunt so fuck off ...
Enter Johnny Walker :D
It is also why Habits (Stay High) by Tove Lo kind of fits a writer mantra song (IMO).