qiān xīn wàn kǔ
thousands of hardships
all sorts of hardships; innumerable trials and tribulations
go through innumerable (or untold) hardships
Tā yòunián sàng fù, mǔqin zài qiānxīnwànkǔ zhōng bǎ tā fúyǎng chéngrén.
His father died when he was a child, and his mother brought him up amidst innumerable hardships