"My youth is bent by the same wintry fever": Time eventually destroys the speaker's youth, just as a fever sickens and endangers someone.
"Turns mine to wax": Time will one day still the speaker's blood when he dies, turning it into a wax-like substance.
"At the mountain spring the same mouth sucks": Time is personified, figuratively sucking at the spring to symbolize it drying over the course of time.
"The hand that whirls the water in the pool": Time is personified again in this line, given a hand with which to disturb a pool of quicksand.
"That ropes the blowing wind": Time can seize control of the wind, which in turn controls the motion of a ship.
"Hauls my shroud sail": Time moves the speaker's sail forward.