。
Don't nitpick about what I do.
Literal
I [of-の] do thing [on-に] fault-finding don't-do [give-くれ].
僕のやること ('things I do') uses こと to nominalize the relative clause. とがめだて ('fault-finding, carping') is a noun formed from 咎める ('to find fault with') + 立てる ('to raise, to set up'). The doublet emphasizes intensity: 'to repeatedly find fault with.' An uncommon but vivid word.