Rehabilitarme means "to rehabilitate me." It's an interesting word choice in a romantic context, as it's often associated with recovery from addiction or injury, not typically with love.
In this song, the singer uses it to express how his beloved angel has brought him back from a lost state, implying that her presence has healed him emotionally and given him a new purpose. This unique usage makes the word stand out and adds depth to the song's message of transformative love.
Ulices Chaidez's "Mi Bello Ángel" is such a sweet song about finding your guardian angel in human form! The singer sees his love as a "hermosa criatura" [beautiful creature] and his "bello ángel que cayó del cielo" [beautiful angel who fell from heaven]. He feels like a "simple, pobre diablo que corrió con suerte" [simple, poor devil who got lucky] to have her, believing it's a divine act that brought them together.
He describes how she's the only one who excites him and makes him lose his way, taking him out of this world every second he feels her. He even says that "entre el cielo y el infierno solo hay un espacio" [between heaven and hell there is only one space] and he loses his rhythm when she leaves him. It's clear she completely transformed him, as he sings, "Siento que después de ti, yo soy otra persona" [I feel that after you, I am another person]. He was lost, and she came to comfort and rehabilitate him. It's a powerful declaration of how one person can completely change your life for the better!