First Edit: On my 36th Birthday

[Todd]

Hi Richard, let me give you some comments.

On my 36th Birthday

I realized today--As opening lines go this is a bit uninspiring. Might I suggest a slight rework: "I realized today I'm six years too late/to copy you. You" If you're going to focus on missed opportunities and regret than breaking the line on late fits more thematically and builds tension. If you have the repetition of you on the next line and then break there you give a reflective pause that suggests the context for the regret. Albeit the copying is a bit morbid and the regrets don't travel down a typical path.
I'm six years too late to copy you.
You, reborn through failed deaths,--I like the entire idea of reborn through failed deaths. It's good phrasing for coming out the other side from attempted suicides or ODs or the like.
while I like to think of dying--This a great break to set up the image and contrast the previous line.
as that far away dog on a prairie plain.

I accept I'll never be like you,--While this is a serviceable line. You might alternatively want to end the last strophe after plain with "I accept" as if it's an acceptance of the idea of dying and dying alone. Then the white space strophe break would play on the isolation of that idea.
there are no metaphors to describe
my uncut thumbs.--I like the leadup to this line but wasn't making a connection to uncut thumbs (could be me just missing something obvious).

But I'll still try to understand you:--Again, you may want to pull up I'll still try to the end of the previous line on the above strophe. There's a halting quality it might add that could be interesting.
disillusioned with love,
burdened with family,
judged by tulips.--That's also an interesting line. I'm not sure in what sense this would be true but I like the wording and idea of it.
You, who transformed suicide
into a poetic device--lovely two lines
by translating death's foreign language
like a prisoner at gun point.-This entire strophe rocks. I like every choice you've made here. Crisp, tight writing.

While I count the candles on my cake,
aware they must be extinguished,--I'm not fond of your last line. I think I'd prefer it to end on this line (that would require some slight changes of course to make it read well).
you live the only way a dead poet can.

I hope some of that helps.

Best,

Todd