Analysis of A Billet Doux

My brightest hopes are mix'd with tears,
Like hues of light and gloom;
As when mid sun-shine rain appears,
Love rises with a thousand fears,

To pine and still to bloom.
When I have told my last fond tale
In lines of song to thee,
And for departure spread my sail,
Say, lovely princess, wilt thou fail
To drop a tear for me?

O, princess, should my votive strain
Salute thy ear no more,
Like one deserted on the main,
I still shall gaze, alas! but vain,
On wedlock's flow'ry shore.