Parálisi' is a colloquial shortening of "parálisis," meaning "paralysis." It's an interesting word because it's not commonly found in everyday song lyrics, making it stand out.
In the song, the artist uses it metaphorically, singing, "Creo que sufro parálisi' estando dormido / Porque estar con vos es un sueño" (I think I suffer paralysis when I'm asleep / Because being with you is a dream). This line beautifully conveys a sense of being so captivated and entranced by someone that it feels like a dream, almost as if he's unable to move or react due to the overwhelming feeling.
Milo j's "A VOS" is a passionate declaration of intense devotion, almost an addiction, to someone special. He sings, "Te di todo lo que tengo / Lo volvería a hacer" [I gave you everything I have / I'd do it again], showing a complete surrender to this person. He's so captivated that even just hearing them speak is "oro" [gold], and losing control over his feelings for them "lo es todo" [is everything].
He describes a love so powerful it makes him feel like he could lose everything else because "nada vale sin ti" [nothing is worth anything without you]. The lyrics are full of vivid, almost dreamlike imagery, like "río mirando el phone" [I laugh looking at my phone] and saying the sun envies her because "brillas como él" [you shine like it]. He even suggests that being with her is "un sueño" [a dream], making him feel like he's experiencing "parálisi' estando dormido" [paralysis while asleep]. It's a beautiful, all-consuming kind of love where he wants to be there for her when she's down and end her loneliness, even asking her to "Cúrame de todos mis males mentales" [Cure me of all my mental ailments]. He's completely hooked, admitting, "Pero ahora soy adicto a vos" [But now I'm addicted to you].