The phrase to go to pot, earlier also to go to the pot, which dates from the 16th century, means to be ruined or destroyed, to ‘go to pieces’, to deteriorate through neglect.
The allusion is to the cutting up of meat into pieces ready for the cooking-pot, as several 16th-century texts make clear; for example the following passage from Apophthegmes, that is to saie, prompte, quicke, wittie and sentencious saiynges, of certain Emperours, Kynges, Capitaines, Philosophiers and Oratours, aswell Grekes, as Romaines, bothe veraye pleasaunt & profitable to reade, partely for all maner of persones, & especially Gentlemen (London, 1542), the translation by the schoolmaster and playwright Nicholas Udall (1504-56) of Apophthegmatum opus (1539), by the Dutch humanist and scholar Desiderius Erasmus (circa 1469-1536):
How Dionysius yᵉ tyrāne vsed his familiare frendes.
To one demaūdyng after what sorte Dionysius did vse, handle, & entreacte his frendes that wer familiare about hym: like as if thei wer bottles, saied he, the fulle he hangeth vp, and the emptie, he casteth asyde in a corner. Signifiyng, that by the said Tyrāne Dionysius the riche & welthie of his subiectes went dayly to the potte, and wer chopped vp, and suche beggery wretches as had nothyng to leese, wer nothyng medleed withall, ne had any thyng saied vnto theim.
(In early use, authors such as Udall may have been punning on pot, a common Scottish and Northern-English word—apparently a variant of pit—meaning a deep hole, and figuratively the pit of hell.)
Likewise, in the following passage from A true & exact history of the island of Barbados (London, 1657), the business agent and natural science writer Richard Ligon (circa 1585-1662) used the phrase in connexion with anthropophagy:
Our victualls too, being at a very low Ebbe, could not last us many dayes. So that all that were in the ship, both Sea-men and Passengers, were gazeing one upon another, what to doe when our small remainder of provision came to an end. But the Sea-men, who were the greater number, resolv’d, the Passengers should be drest and eaten, before any of them should goe to the Pot.
In The history of Whiggism, or, The Whiggish-plots, principles, and practices (mining and countermining the Tory-plots and principles) in the reign of King Charles the First (London, 1682), by the Church of England clergyman and religious controversialist Edmund Hickeringill (died 1708), a character explains his own use of to go to pot:
In Edward 3d. time, poor Thorp, Lord Chief Justice, went to Pot, in plain English, he was Hang’d […] for receiving the Bribe of 100 l in obstruction of Justice.