King James Version (KJV)
Therefore I went about to cause my heart to despair of all the labour which I took under the sun.
Modern English
So I turned about and gave my heart up to despair over all the toil of my labors under the sun.
Hebrew
וְסַבּוֹתִ֣י אֲנִ֔י לְיַאֵ֣שׁ אֶת לִבִּ֔י עַ֖ל כָּל הֶֽעָמָ֑ל שֶׁעָמַ֖לְתִּי תַּ֥חַת הַשָּֽׁמֶשׁ׃
vsabvotiy ʾaniy lyaʾesh ʾet libiy ʿal kal heʿamal sheʿamaltiy taḥat hashamesh