Correct

下半辈子

/ xià bànbèizi / 
Strokes

Example

As a Noun

latter half of one's life; one's remaining years; the rest of one's life

1
Tā
他
shì
是
wǒ
我
xià
下
bànbèizi
半辈子
de
的
wéiyī
唯一
yītuō
依托
  
。

He will be my sole support for the rest of my life.