I think some floor length drapery on either side of the window would do wonders. Something solid and neutral that's darker than the walls, or maybe an eclectic pattern with a bold color.

Get a console for the left side to go along the wall, a buffet with clean lines, or something rustic with a Belgian oak wood. Depends on if you would use it for storage, but something with enclosed cabinets would be best. A proportional square or rectangular mirror above it, to open up the space vertically, and build height.

A rug could be a nice addition, but it's not necessary. Something durable that's flatter so chairs can easily slide in and out. A flat weave sisal would be nice in a dark beige.

I will keep you posted. Thanks I'm horrible at this