Lines from H.P. Lovecraft's "Dagon"

I am writing this under an appreciable mental strain... you may guess, though never fully realise... I must have forgetfulness or death... I had but little idea... I could only guess vaguely... I knew nothing... for uncounted days I drifted aimlessly... Its details I shall never know... one might well imagine... other less describable things... Perhaps I should not hope to convey in mere words the unutterable... nothing within hearing, and nothing within sight... innumerable... unfathomable... I could not detect... an unknown goal... I know not why... immeasurable... black recesses the moon had not yet soared high enough to illumine... fathomless... unfashioned... I cannot definitely analyse... no light had yet penetrated... I cannot express... unknown to me... unlike anything I had ever seen... unknown to the modern world... I dare not speak in detail... beyond the imagination... beyond the conception... I think I went mad then... I remember little. I believe I sang... I have indistinct recollections... some time after... In my delirium I had said much... my words had been given scant attention... knew nothing... they could not believe... I cannot think... I dream... The end is near.