A few years ago, I went through the same thing. I was going through a rather rough time in my life, which you would think would be a prime time to write, but I didn't feel like writing about only depressing things. There may not be anything right now that you can do do get out of your slump. You may just need to wait it out, maby not though. I was writing about mostly deep stuff. For me, my creative plateau ended when I found, and learned to harness my sence of humor. I started to write just crazy funny lyrics. I found that I bacame better at writing serious stuff for some strange reason. I started to carry around a notepad and just write in it; mostely because I have ADD and have the short term memory of a pot head, but it has dramatically improved my writing. I also realized that if nothing changes in your life, how can you expect your writing to change. Try new things, or do things out of the ordinary. But don't stop writing just because its nothing new or exciting. Just writing helps to get the creative juices flowing.