Been there before and sometimes you just need a break. That said don't let it go on too long or the legs will hate you for it. I'm the opposite just now, I'm loving it at the moment. Weathers been ok, trails are fast and by my standards so are my legs. Just waiting on washing machine finishing then off up Glen Esk to drag my Fatbike up a Munro.
I got out of my rut by making plans with friends, that way you feel obliged to go even if you don't feel like it. A couple of us doing the enduro at 10utb on Sunday if you fancy a day away.