I'm sorry to arrive so late in this discussion:
I also wish you a wonderful New Year, Franck!
Now that everything's finished here, I suppose my input comes too late, but:
I do agree, that "brainwashed," with its very negative connotations of purposely manipulating another person's mind for one's own ends, may not be quite the right word
(I can't read Spanish) for what seems to be a more neutral expression, meaning something like "you took the place of all my other memories"?
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The outlines of my life have crumbled,
just when everything was perfect.
And even worse, I can now think only of you.
I keep the memory of you like my best secret,
How good it was to feel you inside.
---
?