What is the meaning of [I have not slept one wink]

I have not slept at all.

The notion of getting not even a single moment’s sleep has been in the language since the 14th century. Robert Manning of Brunne, in his work Handlyng synne, 1303, records the phrase in Middle English:

“Ne mete ete, ne drank drynke, Ne slepte onely a-lepy wynke.”