Unfortunately, when you hit the 'end relationship' button (or when the game glitches and drops a relationship, as many Akaavi-fans have noted recently), there's no 'I'm sorry, take me back' button.

And, regrettably, using a 'skip to Knights/Onslaught/etc.' token results in the game automatically flagging the character as not having taken part in any romances up to that point, and Kira only renews a relationship with a Jedi Knight that had already romanced her before her return.