"me fait surprise" is awkward. It's better to say, "par surprise" or "tu m'as surpris"
"et dans mon rêve" become "et dans mes rêves"
"disparais en silence" is not fine. "tu as disparu en silence"
I would translate, "au plus profond de ma tête", "tu occupes toutes mes pensées"
The french in this song is fine but all the sentences seem a little awkward. But it is difficult to translate in order to match with the rythm of the song.