Estou na dúvida se esse "it" refere-se ao "fim" ou à "vida"
Creio que faria mais sentido estar se referindo à vida (O fim da vida como eu a conheço).
Please Kafetzou, we are in doubt about that "it" in the source. Do you think it refers to "the end" or to "the life" s/he knows? Those words have different gender in Portuguese.
It's a common phrase. The "it" refers to "life", and the whole thing means that life is about to change for this person. "Life as I know it" means "the life I've known up to now".