Hmmm, I see your dilemma! Fortunately, there are lots of ways to work around it! You haven’t mentioned the lighting in your room — if you’re working with just an overhead light or have any lamps. If you don’t, I would say to add in lighting from different heights and angles to help brighten up the room. A floor lamp in the corner, some fairy lights across the ceiling or draped over your bookshelf or wardrobe, or even some small candles or table lamps on different surfaces!
I would try to clear up and declutter the surfaces and bookshelf of your room as much as possible. Try to get as much room as you can to add in accent pieces. Some faux or fresh flowers, smaller pieces of art, crystals, marble accents, or small metallic accents could all bring some liveliness and lightness into the room! Also, I don’t recall you mentioning curtains, but if you have or can get curtains in your room, a thin, white, gauzy curtain would bring a lot of whimsical, bohemian lightness into the mix!