I've had to deal with much more trying circumstances than this.
Yoshiさんの英文、I’ve been through much worse than this. で完璧ですよ!
または次のような言い方もできます。
ーI've had to deal with much more trying circumstances than this.
「私はこれよりも辛い状況を対処してきた」
to deal with「対処する」
trying circumstances「辛い状況」
ご参考まで!