I have been thinking it over and over and I came up with an idea what could be the cause (there is a small chance it is like this, but I cannot rule it out).

The keyboard of my old computer was sometimes malfunctioning, e.g. letters that did not appear on the screen despite hitting them.

Could it have been, that one or two letters continuously were not hit, while I thought I typed them and therefore wrote down on paper another password then I typed?

That could explain something. The shitty thing is, I later destroyed my keyboard when I trew over a glass of water, so now trying to get that computer to work and retype the password there is not going to work.

If however this is the case, bruteforcing it might help. But still, in my attempt to create a safe password I created a phrase of around 35 letters and numbers , so I am not sure how feasible it is to crack it...

In the mean time, I will keep looking for solutions. Any insight or advice is highly appreciated!

Best,

Clochard