Especially used in the phrase all of a tiswas, the British-English noun tiswas (also tis-was, tizwoz, etc.) denotes:
– a state of nervous agitation or confusion;
– also, occasionally: a state of physical disorder or chaos.

This noun is of unknown origin. It may be a fanciful variant of the synonymous noun tizz.

The earliest occurrences of the noun tiswas that I have found are:

1-: From If You Can Think of a NEW Sport . . . YOU’LL MAKE A FORTUNE, by Denis O’Sullivan, published in the Daily Mirror (London, England) of Tuesday 5^th July 1938:

TEST team chosen in pub. . . . Oh, Jeames [sic], quick! The eau-de-cologne, sivvy-play! The news has knocked me all of a tis-was.
Dearie me, if such a sacred ceremony can be carried out amid the plebeian odour of hops—why, anything’s possible.
Any moment now Hitler’ll be ending [sic] up a note to Chamberlain with “Love and kisses, Adolf.” And it’s even on the cards that folk like you and I might some day get bang in the big dough.

?-: [On Thursday 12^th January 1939, both the Bristol Evening Post and The Western Daily Press and Bristol Mirror reported that the Bristol Corporation Electricity Department Dramatic Society had entertained the patients at Eastville Institution, Bristol, England, with a revue titled Tiz-Waz. But those reports did not say whether the name Tiz-Waz had any signification.]

2, 3 & 4-: From Local Notes & Queries, published in the Somerset County Herald & Taunton Courier (Taunton, Somerset, England):

2-: Of Saturday 29^th May 1948:

4364.—“Tis-Was.”—I have been reading Monica Hutchings’s ¹ latest book, Hundredfold, in which, referring to the difference between our present summers and those of long ago, she makes one of her characters say:—“If you d’ get a two-three days fine together you’m all of a tis-was and complainen o’ the heat.” Could you or any of your readers tell me what a “tis-was” is? Is it a genuine Somerset dialect word?—M.

¹ Monica Mary Scott (1917-1977) wrote numerous books, mainly about the West Country (i.e., the south-western counties of England, especially Cornwall, Devon and Somerset), under the name of her first husband, Herbert Laurence Roy Hutchings (1916-1992).—Source: Find a Grave.

3-: Of Saturday 19^th June 1948:

4364.—“Tis-Was.”—This word is entirely new to me. I have tried to find out something about it, but no-one whom I have asked has ever heard the word used. I doubt if it is a part of our dialect currency—at least in this part of Somerset. It appears to me to be an expression made up on the spot and for a particular occasion, an art in which the countryman is an adept.—D. J. Gass, Castle Cary.

4-: Of Saturday 26^th June 1948:

4364.—“Tis-Was.”—In reply to your correspondent who, having read “Hundredfold,” expresses interest in the phrase “all of a tis-was,” I had it from neighbours in this village, who use it with some frequency. They are Somerset people born and bred. I also seem to recall having heard it used in Chard when I was a child. In view of the fact that the phrase is used in this village I am rather surprised your Cary correspondent, who lives so close, has not heard it. I should have thought, too, that the context rendered the term self-explanatory, it approximates to “all of a dither.”—Monica Hutchings, South Barrow.

5-: From the Daily Mirror (London, England) of Monday 3^rd November 1952:

The girl with the goo-goo eyes

I’LL tell you, girls, I had a boy friend out in Bafwasende ² who couldn’t look at my eyes without going into a tis-was. “Ellie,” he used to say—they called me Ellie then, but my name is Gorgeous now—“Ellie, your eyes are like jewels fringed with silk,” he used to say. “Go on with you,” I’d say, pecking him in the rump, “you’re only saying that because it’s true.” Oh, I had all the lads after me in Bafwasende, Belgian Congo—and you’ve simply no idea what lads terrestial [sic] hornbills can be. Now I’m in London Zoo.

² Bafwasende is a town in the Democratic Republic of the Congo, a former Belgian colony known as the Belgian Congo from 1908 to 1960.

6-: From A feature for women, by ‘Annabelle’, published in the Torquay Times and South Devon Advertiser (Torquay, Devon, England) of Friday 9^th May 1958:

E.A.W. COOKERY COMPETITION
TORQUAY’S Electric Hall was a busy hive of activity on Tuesday afternoon when the South-Western area finals of the Electrical Association for Women’s national cookery competition, sponsored by the Egg Marketing Board, were held.
[…]
The winner, who will represent the South West in the national finals in London next month, was Mrs. Marjorie Pender, of Taunton. She told me: “I’m all of a tizwoz.”