screw up courage meaning in English

鼓起勇气，奋勇

I wrote it and screwed up courage to go down to the bulletin after hours , intending to drop the thing into the letter box , but , just as i was about to do so , or rather making up my mind as to whether i ' d shove it in , or take it home and have another look at the spelling and the dictionary , he door opened suddenly and a haggard woman stood here
我写下了它，并且在几个小时后鼓起勇气走到了公告栏下,想要把它投进信箱,但是,正在我就要这样做时候,我想是不是要把它推进信箱还是回家查查字典再看一遍拼字，门突然打开了，一个憔悴的女人站在那里。