I would move the tv to the wall where the couch is now. Move the couch opposite, with its back to the sliding door. Consider adding a sofa table behind with a pair of lamps to bring more warm lighting into the room. Keep the small chair where it is on the right side of the fireplace, and use the floor lamp next to it. Put the chair and a half and ottoman to the right of the couch, the end table and lamp beside it. Move the whole arrangement a bit closer to the fireplace, and make sure that the front legs of the couch and the chairs are on the rug. I agree that the coffeetable is not the best choice. I would love to see something round, perhaps a wood or slate top, with iron legs so that you don't have so much heavy furniture in the space. Down on the end wall where the tv is now, I would think about a game table and chairs in the corner where the screen is, great for snacking or playing games or doing puzzles. I would find a new home for the screen. Then a group of bookshelves with some closed storage in the same finish as the tv cabinet to the right along the wall to allow for storage of some of the toys, as well as a place to house books and media. Take the clock off the fireplace and use that on the end wall where the game table will be. Use the canvas you have on the fireplace, to bring some of the warmer colors of the room onto the grey fireplace. If your DH doesn't want to paint the fireplace, check into staining it. Just giving it a warmer finish would do a lot for the room.

After looking at the space, I think I would have a sofa facing the TV and a sofa or 2 chairs, swivel, facing the fireplace making an L shape. I would move the TV stand towards the left as you look at it. It will give you more space for a couch centered on the area. Here are pictures of chairs flanking a fireplace.....https://www.google.com/search?q=chairs+flanking+fireplace&rlz=1C1CHZL_enUS746US746&tbm=isch&tbo=u&source=univ&sa=X&ved=2ahUKEwiF-_PCwcHeAhXl1IMKHdD2Ap4QsAR6BAgGEAE&biw=1600&bih=789

I think you are very much on the right track with your current layout, I would make a few tweeks, place the tv on the wall opposite the fireplace, similar to where you have it but not an angle, put it on a long console that will take up most of the space on that wall, console if possible be floating or open at the bottom, something like the pics below. keep sofa where it's at and then add a couple swivel chairs where you have the current chairs and then possible a couple more smaller size chairs flanking the fireplace, add a narrow rectangular coffee table, some side tables and lighting.

Well, let’s get you unstuck! So when you have a long, narrow room, you would want to break it up into “zones” depending on how you live and your family’s needs/wants. I created 3 zones-living, office, lounge/gaming/crafts/puzzles area. I moved the tv in between the windows so it is opposite the fireplace and you no longer have competing focal points with the two sofas facing each other. The round table in between the two chairs could be an adjustable height coffee table(they have ones now that can go to dining height) so that give you a lot of flexibility on how that area is used. If you have young children, that could be a play area.