I'm really not persuaded by your story because you don't actually seem to be engaging in "never break the chain" behavior. Like, can you tell me exactly how many days in a row you've journaled? Like, if you had a counter going in Duolingo or put a red X on a calendar every day in a row that you wrote a joke like Jerry Seinfeld? You seem to be engaged in the system of "do the thing almost every single day, however small, forgive yourself when you miss it" which is a wildly more applicable and effective system, in my opinion.
I think the last time I forgot to journal was... maybe a year and a quarter ago? I fell asleep before I intended to, and when I woke up, realized I had missed a night. I have never ever decided not to journal on a particular night, and this fact is enormously motivating. That is why the chain system is useful.
One interesting question is, how do I journal when it is extremely impractical? The answer is, I've done whatever was necessary to maintain the chain. Lacking a journal, I've used a pen and scrap paper. Lacking any writing utensils, I've used my phone. Lacking my phone, I've borrowed someone else's phone. The important part is that I made the sincere choice the perform the action, in however nonstandard a way, and this reminds me of my commitment. I've essentially inducted myself into my own religion.
The difficulty that people run into with maintaining daily rituals is that they have no way of reliably enforcing the ritual during a period of low motivation / energy. My approach is to find a low-commitment version of the ritual to be performed on days where you don't feel you can really give it your all. How I approach this with diary writing is simple: on nights where I feel I cannot possibly spend much time writing, I write an entry of the form, "It is incredibly late and I do not want to write more before I go to sleep." Nothing more. By doing this, I am able to maintain accountability without torturing myself.