Analysis of Sonnet 104: Envious wits

Envious wits, what hath been mine offense,
That with such poisonous care my looks you mark,
That to each word, nay sigh of mine you hark,
As grudging me my sorrow's eloquence?

Ah, is it not enough that I am thence?
Thence, so far thence, that scarcely any spark
Of comfort dare come to this dungeon dark,
Where rigorous exile locks up all my sense?

But if I by a happy window pass,
If I but stars upon mine armor bear
--Sick, thirsty, glad (though but of empty glass):

Your moral notes straight my hid meaning tear
From out my ribs, and puffing prove that I
Do Stella love. Fools, who doth it deny?