Furniture from Home Hi Ladaza, we are currently building a bed for a client that is exactly like this. We are based in Southern California and can ship nationwide. Email sales@furniturefromhome.com for a quote or visit us online: http://furniturefromhome.com. Thank you!
You may need to paint your walls darker, or use darker finishes, fabrics to swallow up some of the empty feeling in your space. Finishes and fabric can fool the eye.
Also use more decorative items to fill in voids - Plants, shelving on walls, large pillows on couches, colorful area rugs to diffuse the eye and give the illusion of more activity happening in your space.
Consider getting additional furniture, maybe a few larger pieces to fill it out. Also consider using artwork on the walls at eye level to bring the eye down.