I stumbled upon one of Wallace Stevens' letters, dated to 1909, where he describes a Sunday walk. I'm intentionally quoting quite a bit of this text, to give the full context (You can read it here; bold added):
"I am quite shattered by the walk I took yesterday - not less than thirty miles. [...] Yet it was, as you say, such a glorious day [...] I passed a camp [... where] they were broiling ham. [...] I did respond to that sugarey fragnance [...] You know - when you camp in wild places - and come in at the end of the day, you always find venison over the fire, or a dozen trouts - and then, there is the hot bread, and your pipe afterwards [...] and you fall asleep, so tired, so contented. [...] And when I reached home I was too dusty and worn out to write [...] I fell all over the bed in a hump. Next Sunday I hope to do the same thing.
It could be that I'm reading too much into it, but I couldn't find a satisfying definition for this usage of the word "hump" (Or the phrase "In a hump"). I'll paste here Merriam-Webster definition as an example:
Definition of hump
1 : a rounded protuberance: such as
a : humpback 1
b : a fleshy protuberance on the back of an animal (such as a camel, bison, or whale)
c (1) : mound, hummock (2) : mountain, range the Himalayan hump
2 British : a fit of depression or sulking
3 : a difficult, trying, or critical phase or obstacle —often used in the phrase over the hump
What does it mean, in this context?