Here is the original of poem 90 of the Rime sparse, quoted above in translation.
Erano i capei d'oro a l'aura sparsi
che 'n mille dolci nodi gli avolgea,
e 'l vago lume oltra misura ardea
di quei begli occhi, ch' or ne son sì scarsi;

e 'l viso di pietosi color farsi
(non so se vero o falso) mi parea:
i' che l'esca amorosa al petto avea,
qual meraviglia se di subito arsi?

Non era l'andar suo cosa mortale
ma d'angelica forma, et le parole
sonavan altro che pur voce umana:

uno spirto celeste, un vivo sole
fu quel ch' i' vidi, et se non fosse or tale,
piaga per allentar d'arco non sana.

I don't think there's any wild exaggeration in this. Capei d'oro = golden hair; oltra misura = beyond measure; these are reasonable.

Non era... cosa mortale / ma d'angelica forma = was not a mortal thing / but of angelic form. Well, can't you say that about someone you know? Le parole / sonavan altro che pur voce umana = Her words / sounded different from a human voice. Again, that sounds like a lover's sensitive perception, not a misperception.

Un spirto celeste, un vivo sole / fu quel ch' i' vidi = A heavenly spirit, a living sun, was what I saw. This is metaphor, but hardly extravagant. He loved her, that was all.

Some of this imagery is taken from Virgil, in book I of the Aeneid, when Aeneas sees his mother Venus disguised as a mortal huntress. She carried a bow and her hair was knotted and her gown disordered in the wind. She asks him whether he's seen a sister huntress, but he answers her in awe, seeing in her look and her voice a sign that she must be some god or nymph. She tells him the story of Dido (on whose coast Aeneas and his crew have just been cast up) and sends him on his way. Only with her final departing movements is it clear that she is the goddess his mother. Petrarch is saying that Laura touches his heart with that sudden realization of something awesome and beautiful beyond all reason.

I recommend knowing someone who can take your breath away like that. :-)