Was it new to you before you went on break or have you had it for awhile? Sometimes new plants will do that, but they'll perk back up again (just getting used to the water changes and such, and sometimes you might need to use fertilizer, depending). Also, if it's new, as Blueberrybetta said, make sure the rhizome isn't buried. I know I'm guilty of that a lot myself.
Blueberrybetta Shannon529 the rhizomes are attached to small peices of wood to help weigh them down but are floating in above the gravel. I've had it since the beginning of January and I used flourish excel before I left for 2 weeks (? I kinda forgot when I got this exactly) dosing after my water changes using a very small amount. I also have flourish comprehensive that I've used one after I got back. Tomorrow is water change day.