I've been watching way too much Clean House and reading up a lot of Feng Shui and Clear Your Clutter books. Here's some of my suggestions (that I'm also implementing in my own room at the moment).
1. Get rid of anything that you don't like, hate, and can't stand. The sooner the better because every time you look at it, it drains your energy because you don't like it. So get rid of your light fixture, get rid of the rug, the light over your kitchen table, and couch pillows. List them on Craigslist, or some other free classified ad, you can sell them to other people who will appreciate it, plus it'll help you fund your new things.
I like this rug for the record:
http://www.rugbuyonline.com/store/en_viewItem.asp?idProduct=4720&ProductDescription=Contemporary
I think it complements your yellow walls really well.
2. I'm not judging, get rid of your clutter. It will make you feel sooooo much better! Clutter drains your energy as well. I have clutter myself, in fact my mom is the clutterbug of the family (I'm trying to help her change). Little by little I've been working on my own clutter these past few weeks. Start small, one corner or one table space, and make your way to the rest. You'll feel the difference immediately! I got rid of (sold off) old bags I don't use, recycled so many college readers and papers, recycled old magazines, donate old clothes or other items for tax deduction. Once you start clearing up diff parts of your home, that feeling is contagious and soon enough you'll go through your entire home. For me, once I started clearing a small pile of clutter in my room, I moved on to other parts, and on and on and I even cleared up clutter on my office table at work. After all this cleaning, I wasn't tired, I was refreshed. My rule of thumb of getting rid of things: if I haven't used it in the past 2 years, maybe someone else can appreciate it more than I did, unless the item has some significant meaning/memories attached to it.
3. Get things that you will love an appreciate because that will reenergize your home. I know you already started looking for different decor items. Rule of thumb is if you love it get it, if you're iffy iffy on it, pass up on it. So regardless of what we think, you need to trust your own instincts, if you love it, if something particularly stands out, say to yourself can I live without this? will this make my home so much better? Hopefully that can guide you to picking the items that represent you the most.
Good luck
I am looking forward to see the changes you made in your home ^___^!