Green’s Dictionary of Slang

1. drunk [f. stitch-back under stitch n.¹ ].

1737		B. Franklin ‘Drinkers Dict.’ in Pennsylvania Gazette 6 Jan. in AS XII:2 92: They come to be well understood to signify plainly that A MAN IS DRUNK. [...] He’s Stitch’d.
1951		Cusack & James Come in Spinner (1960) 334: Bloody top-weight’s got you all stitched.

2. (Aus.) defeated [stitch v. (2)].

1968

S. Gore Holy Smoke 8: Always talkin’ about how they’ve got everyone else around the place stitched.