The phrase tired and emotional, or tired and overwrought, is a jocular euphemism for drunk.

It was coined as tired and overwrought in the British satirical magazine Private Eye (London) of 29^th September 1967 (the British Labour politician George Brown (1914-85), who had a drinking problem, was at that time Secretary of State for Foreign Affairs):

Mr George Brown had been tired and overwrought on many occasions.

Joseph W. Grigg evoked the image in ‘Brother Brown’ on the Way Down?, an article about George Brown published in the Courier-Post (Camden, New Jersey) of Monday 9^th October 1967:

On some occasions Brown has been described by the very libel-conscious British press as being “tired” or “overwrought.”
But it took the mass circulation pro-Laborite tabloid Daily Mirror to mention the word “drinking” in connection with him.

I have not found any record of the form tired and emotional in Private Eye itself, but the following from the column Boston on Beer, by the English journalist Richard Boston (1938-2006), published in The Guardian (Manchester, Lancashire) of Saturday 10^th August 1974, indicates that the satirical magazine did use the phrase in this form; after giving synonyms for drunk from Roget’s Thesaurus of English Words and Phrases and from The Water-Drinkers: A History of Temperance (London, 1968), by the English historian Norman Longmate (1925-2016), Richard Boston wrote:

To these one could add jarred, jugged, bottled, pickled, bevvied, had a few, had enough, steamin’ (Glasg.), plonked, smashed, high, tanked, mortal (Scot.), steamboats (Lowland Scot.), sloshed, tiddly, under the influence, got a few inside him (or her), tired and emotional (Private Eye), half cut, well away, high as a kite, pissed as a newt, and tight as an owl.

The earliest real use of tired and emotional as a euphemism for drunk that I have found is also from Boston on Beer, in The Guardian of Saturday 24^th August of the same year; Richard Boston told that Richard Ingrams, editor of Private Eye, a neighbour and he walked along the entire length of the Ridgeway, which runs from Streatley to Avebury for some 45 miles; after the walk, they

drove to Kintbury where there’s a delightful pub called the Dundas Arms on the Kennet and Avon canal. The beer (Morland’s) is excellent, and you don’t have to walk 45 miles to think so.
The food too was outstanding, but unfortunately I fell asleep during the meal. This, along with my difficulty in standing, may have wrongly given the impression that I was tired and emotional. I was certainly tired and slept very well that night.