I say take a break if you feel like you aren't playing optimally because of the downswing and/or because what type of psychological affect its having on you as a player.
If you don't feel like your game is being affected too much and you're still playing optimally, but just on the bad side of variance, I suggest you continue playing. However, maybe reduce the number of tables you're playing or down down in stakes until you've built yourself back up and/or are on an upswing.
Another thing that might work, if you wish to continue playing, is to play something else. Maybe cash games need a break and you can play more SNGs or MTTs. Basically a break from the normal routine.