Have you ever considered moving the couch against the window? Does it fit? I think it would open up the living room. I'm just not sure if the L shape of the couch will create an unwanted "wall" between your dining area and living room.

A quick fix to add more color or brightness to the room can be by adding colored pillows.

Agree with Stanton on the subject of your art. It is too small for the walls and it is too high up too. I wouldn't put a mirror above the couch though. You have such big windows, there is enough light in your room. Only your furniture and floor are dark. You've got a good rug though.
Red isn't the best accent colour to brighten a space up. So lighter curtain panels would be nice and if you add pillows and perhaps a throw to your couch it will break up the darkness of that.

I'll see if I can find you some inspirational examples.

I agree with Skyler. If it fits and does not block the way too much, would look much better. If not try where the Tv is? yea bunch of comfy pillows with many collors and patters and wraps also colourful

sorry I mean colours and paterns and blanckets

Whenever you want a space to look larger you must ELIMINATE CONTRASTS. That means if you are keeping the dark sofa and TV, you need to paint the walls a darker color to "blend" with the dark floors and furniture. Even a medium gold close to the table color will help. I agree with Stanton a very large mirror behind the sofa would help with lightness and make the space look larger.

@Skyler & Izzifly - The couch was there before, felt too enclosed. We just moved it where it is and it has opened up the space. But the other ideas are great and much appreciated :)

What about where the table is and tv where the couch is and table where the tv is. Just suggesting this made me exausted. Invite some friends over on a weekend serve some munchies and drinks and a price for the one with the best idea. Have fun