Hello.
My first remark would be to point out that the song features some modifications to the original poem by Pedro Homem de Melo. These modifications, probably aiming at poetic effect, seem to obscure the message of the poem. Therefore it might be useful to read the original here: http://www.nicoladavid.com/obras-de-pedro-homem-de-melo/cuidei-que-tinha...
Although not a native speaker of any of the languages in question, please allow me several suggestions as to the translation:
porventura as adivinhas -> perhaps you guess them (in the sense "read them", "demystify them")
Meu amor, quando me enlaças. -> my love, when you embrace me (simply)
tirar de mim o sentido -> make sense of myself (in the sense of "try to find the meaning of myself")
Cuidei que tinha morrido -> I supposed I had died
Thank you for the translation!
Tomasz
Poesía de Pedro Homem de Mello- Música de Alain Oulman