I agree to keep the TV where it is. Try removing the art that you have over the couch. Then make a cut-out of cardboard or paper in various sizes to mimic artwork. That will help you get a feel for what would work on that wall. I'm thinking one large picture flanked by larger more substantial sconces hung closer to the artwork.

If you don't want the other wall to be empty try getting one large piece of art for over the sofa:

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