I think the way to brighten your room is with some color. Get some colorful throws/throw pillows and art.

I see a window???? IMO Gray is drab and is going to always make you feel less bright. I would make sure you have 3000Klight bulbs. Look at small scale sofas with straight up arms - not cured out like the one you have now.

I think the first step to brighten up the space would be to get rid of the gray rug.