I actually know better the slightly different Dominican chant recension (which omits the words gloriosa et), but find this - the Roman version - quite singable.
What an excellent prayer! As all men know, this is the oldest known prayer to Our Lady, about 1750 years old in fact; the English version I know, based upon the Latin, is:
We fly to thy patronage, O Holy Mother of God: despise not our petitions in our necessities, but ever deliver us from all dangers, O glorious and blessed Virgin.
Of course, there is an ambiguity in the Latin: does semper go with libera nos, or with Virgo - in other words, do we pray "ever deliver us" or do we pray to the "ever Virgin"? So long as this is kept in mind, I feel that either is perfectly reasonable; and I normally say this prayer in Latin anyway. (Some forms of the Latin prayer include the word nostris after necessitatibus, but this is not necessary for the sense.)
The oldest version of this prayer is found in a Coptic manuscript, in Greek; the prayer continues in use to-day in the Byzantine Rite, as an apolytikion at the end of Vespers in Great Lent, thus:
Ὑπὸ τὴν σὴν εὐσπλαγχνίαν,
Τὰς ἡμῶν ἱκεσίας,
μὴ παρίδῃς ἐν περιστάσει,
ἀλλ᾽ ἐκ κινδύνων λύτρωσαι ἡμᾶς,
μόνη Ἁγνή, μόνη εὐλογημένη.
Beneath your compassion,
We take refuge, O Mother of God:
do not despise our petitions in time of trouble:
but rescue us from dangers,
only pure, only blessed one.
(Thanks to Wikipedia for this and its translation!)
Note that the Latin adds sancta ("holy"), cunctis ("all"), and semper ("always/ever") - all customary amplifications of euchological texts - while it renders εὐσπλαγχνίαν (goodness of heart) as præsidium ("assistance/defence/stronghold"; englished as "patronage"), and paraphrases μόνη Ἁγνή (only Pure/Chaste) as Virgo; perhaps "only" suggested semper ("always") - it appears that gloriosa et is indeed a later amplification of the original. My dictionary explicitly equates κίνδυνος with periculum, but suggests that λύτρωσαι would be better rendered as "ransom/redeem" - redime.