「by」と「until」の違い

A few days ago, by either a huge mistake or miracle, I managed to take a picture of myself as I was trying to turn off the alarm. In the morning, I'm a zombie. Look! There's even something on my nose. Gross!

• 奇跡 (きせき) (n) miracle; wonder; marvel; (P);
• 奇蹟 (きせき) (n) miracle; wonder; marvel;
• 驚異 (きょうい) (n) wonder; miracle; (P);
• 神業 (かみわざ) (n) divine work; miracle; (P); (definitions from Edict)
  
• gross 気持ち悪い、嫌な、ゾッとする、吐き気を催すような、いまいましい、ムカムカさせる、むかつく (definition from Eijiro on the Web)
  

× I'm not coherent by the time I drink some tea.
◯ I'm not coherent until I drink some tea.
筋の通った (すじのとおった) rational; logical; coherent; (definition from Edict)

× Usually I'm not a zombie until I leave the house. <- it means when I leave, I become a zombie! This is not true!
◯ Usually I'm not a zombie by the time I leave the house.

• "by" (prep) + __(a point in time)__ (amount of time used is unclear)
• "until" (prep/conj) + __(a point in time)__ (amount of time used is clear)
• point in time = date, clock time, condition

× That's because on most mornings, I've had a cup of tea until 9 am. <- huh? I don't think we use "until" with present perfect tense.
◯ That's because on most mornings, I've had a cup of tea by 9 am.

× Please study this post by the time you understand it.
◯ Please study this post until you understand it.

If I don't go to sleep soon, I'll be an even more gruesome zombie in the morning. Good night!

• 悽絶 (せいぜつ) (adj-na,n) extremely weird; gruesome; lurid; ghastly; (definitions from Edict)