Look at your room from a bird's perspective. Is there an area that could have been made into a closet? Ideally, this would go right across an end of the room. You could move the metal cabinets and your wall shelving/boxes up against this wall and hang a curtain right across that end of the room. Use the channel system they use in hospitals to hang curtains from the ceiling. This is cheaper than new furniture and I would bet you have some fabric to make a curtain out of - OR use a quilt or two. I love the amount of space you have, it's just cluttered for me and I would think you could relax and create better in a calmer space.