for one's life
for dear life
like one's life depended on it
despo
hard up
overdesperate
in the worst way
cry for
cry out for
in extremis
desperate
do-or-die
clamant
time-sensitive
imperious
acute
scamblingly
snorter
ultraurgent
hard as iron
dys-
superdifficult
murderous
harder than Chinese math
mountainous
cry
superurgent
fiendish
hard as Chinese algebra
frenzy
wished-for
longed-for
frantically
yearned-for
big
time-critical
despairingly
despondently
hurry
make hard work of
flounder
craved
tall
desired
choosy
desperation
taxing
tightrope
rough
ambitious