Try a different type of music. If I ever get bored of playing bass I listen to a new type of music and jam along with that.
I used to be into rock - def leppard, motley crue, iron maiden that kind of thing.Over a couple of weeks I stopped playing bass and listening to music completely as I was fed up with it. But I thought to myself, this is what I want to do, you can't stop so I picked up the bass and instead of playing along with rock songs I picked a genre I hated, at the time, Rap and played along with Eminem and NWA etc. and then from there I got into Hip-Hop and now I love all of that stuff and listen to it more than I do rock music.
Hope it doesn't last too long