Normally when a popular anime series reaches this point, a production studio creates a number of filler stories penned by another author, which have no impact on the continuity of the main story. However these fillers are usually poorly written and generally rather dull.
There's no announcement yet as to when Fairy Tail will return to our screens, but hazarding a guess, given the current situation, we may be looking at around a year before we get to see some new action-packed wizarding battles.
If that seems like a lifetime, it may be useful to know that the show ends with the events that take place in chapter 297 of the manga; fans of the show can pick up the story from there. Currently the manga is up to chapter 325, so there's plenty to read (24 volumes have been published in English).
Hopefully we won't have to wait too long for Natsu and friends to return to our favourite anime channel; and even if we do, we can rest happy in the knowledge there are loads of cool new shows coming out this spring and summer.