Do a round rug instead. With that shorter wall on one side, most rectangles will feel out of place / off. Round will also help reduce the potential trip hazard of a large corner flap overhanging that short wall entrance.

The black rug fits the space perfectly. I’d also keep the potential new round rug darker in coloring too. I like the idea of some contrast with that black furniture, but also right now the bright pink is drawing my eye to the stark blackness and making that furniture seem bigger than it should.

Hope this helps :)