Hello Mini,
You may choose among:
"Il est possible que je doive te/vous dire adieu." (It is unclear whether the action takes place in the present or in the future.)
or "Peut-être dois-je te/vous dire adieu." (The action takes place in the present.)
or "Il me faut peut-être te/dire adieu." (The action takes place in the present.)
or "Peut-être devrai-je te/vous dire adieu." (The action takes place in the future.)
or "Il me faudra peut-être te/vous dire adieu." (The action takes place in the future.)
In these sentences, "you" should be translated by either "te" (informal) or "vous" (formal).
Best regards,
Muriel