The phrase "a digression from" is correct and usable in written English.
It is used to indicate that a particular phrase or point is straying from the main topic of the discussion. For example: "This is an interesting thought, but it's a digression from the main idea we were discussing."
Anyway, that's a digression from a digression, which is good going for paragraph one.
The hard fact of it was that ornithopters, machines with flapping wings, were a digression from the path that led to the airplane".
"My whole life since," the narrator says, "has merely been a digression from those days, which now hang over me like a quarrel that will never be resolved".
But the most haunting moment came with a digression from the musical depiction of emotions, or affects, to the depiction of objects and events.
Les Misérables begins with a digression from a digression (thus resembling Gustave Flaubert's Madame Bovary, which a few years earlier had begun with a digression, too).
"My whole life since,'' the narrator says, "has merely been a digression from those days, which now hang over me like a quarrel that will never be resolved".
A characteristic digression, from a column on Donizetti's "Dom Sébastien": "Among the Scribe papers in Paris I discovered an affidavit to the effect that the composer had rewritten the baritone's principal air, 'Ô Lisbonne,' between the dress rehearsal and the first night … The next day, I found the original air — a beautiful piece — in the baritone's partbook".
Soon I had established a private ideal of how phones ought to be arranged, any digression from which -- a Princess phone, say, in a kitchen -- caused me real distress.
"He is constantly digressing from his own tangent, so he's digressing from a digression".
A lot of time was wasted with unnecessary things – much of it was spent talking about a giant rabbit, a big digression from the main plot.
She introduces her stories of Clara's mixed-race ancestry in Edwardian Jamaica, for instance, with a sudden digression from the name of the comprehensive school that her daughter attends ("A more thorough investigation in the archives of the local Grange Library would reveal... ..)... ..
