I can relate to the voices thing. They can be very crippling if you let them. Just two things I noticed. The voices tend to appear and reappear when stressors show up in my life. It might help to examine your environment and change things around a bit if something is making you very stressed (like your current living conditions, perhaps?). The voices get worse or fade away depending on whether or not you fuel them. I like the idea of just observing your thoughts as an insider; the opposite is choosing to actively facilitate the negative spiral of your thoughts.
Anyway, thanks for starting this thread. I got a couple of books that seem worthwhile to read out of it.