I don't understand the "And yet."
The "and yet" was meant not as a comment on that, so much as saying that the mistress may have beauty, but it is a false thing. Sort of a "you are beautiful, and yet your beauty is a false thing. It tempts only the base." I'm saying love is lost in the lust, in the second stanza. The first stanza says that she's beautiful. The second that it's only lust, and base. The third is saying, essentially "f*** it. If you'd be with me I wouldn't care for any of that." She would still be cared for. The final couplet says, essentially, to hell with both love and lust. Happiness is all that matters.
Your advice on the abstract/physical, and the separation of ideas in stanzas is good advice. I'll take it on board for the future! To be honest, I need to keep that sort of thing in mind more often. I tend to write and then think afterwards
I am a man: two paces' worth of land
Alone am I allotted at my birth;
Though falsely more can I claim I command
Yet still my own is but that shallow earth.
Of much I say "I am," and "this is I,"
So much and oft that I believe it true;
But now I see, through clear and borrow'd eyes,
That I am not "I AM," but "what I do."
My name is not star-written on the Way,
For mine is but the lot of mortal men;
And all I have are six short feet of clay,
And naught but deeds can I bring into heav'n.
So it is not by Fate's, but by my hand
That I resolve to be more than a man.
Traditionally the couplet at the end is meant to rhyme, but that is of course optional - I don't know if you left it out deliberately or not. "Two paces' worth" should probably be "two paces worth."
The message is one that I like. Many argue that the sonnet is the love form of poetry - of course it isn't just that. It is often used for other things, and the contrast between the typical love poem and the poem that is different can be quite striking. Speaking, as you are, of the grave, and how actions are all that count, not possessions, is interesting in that context. You slip the metre in the third to last line, "into heav'n." The extra syllable would not matter so much, were it not for the apostrophe which I feel limits its ability to rhyme with "men."
The only question I would have is who the borrowed eyes belong to?
For all aspiring poets, i've found that allpoetry.com is a really great site to get feedback and inspiration on. Check it out.
Thanks for sharing! Definitely looking into this.