Jamieson, Fausset and Brown on Jeremiah 13:21

21. captains, and as chief--literally, "princes as to headship"; or "over thy head," namely, the Chaldeans. Rather, translate, "What wilt thou say when God will set them (the enemies, Jr 13:20) above thee, seeing that thou thyself hast accustomed them (to be) with thee as (thy) lovers in the highest place (literally, 'at thy head')? Thou canst not say God does thee wrong, seeing it was thou that gave occasion to His dealing so with thee, by so eagerly courting their intimacy." Compare Jr 2:18, 36; 2Ki 23:29, as to the league of Judah with Babylon, which led Josiah to march against Pharaoh-necho, when the latter was about to attack Babylon [Maurer].

sorrows--pains, throes.