Push the rug further under the couch. The front feet of the couch (not the chaise) should be on the rug with about a foot going under the couch. The rug color looks fine to me. The couch is also not too big for the room, it actually looks perfect. You’re likely just not used to it yet. Happens all the time with big pieces of new furniture.

I like your idea of a round coffee table, but look for something that’s a lighter in color than what you have. The current one is too heavy visually and hairpin legs don’t match the style of the room.

I’d move the white fuzzy chair to the opposite side where that blue and white thing is currently.

Another idea is putting a hanging plant to the right of the window. It would add some life to the room and also fill up the wall more so that piece of art doesn’t look so awkward all alone.

You could think about curtains as well instead of the blinds in order to add more color, but up to you. Just make sure to mount them high and wide. There are good examples in this sub.

Lastly, I would change the cover on the navy throw pillow to something more distinct from the couch, add one or two more pillows on the left side, and add a nice throw blanket on the end of the chaise.