obsessive strange thoughts about life and existentialism

I have a very serious problem that maybe you can explain. I have been having these 'episodes' where sometimes I forget where I am at and I have these obsessive strange thoughts about life and existentialism, usually it comes out of nowhere and I think about how weird it is that our language is compiled in to the words that we use. I think about how weird that is, and then I start to panic because I don't understand what is happening to me. Like I will look at a word for example 'question' and I will obsess on how weird it looks and sounds when we communicate and read it in a sentence. I know it sounds bizarre, but it is really scaring me! I also am afraid to go to sleep at night because when I hit REM, I am half aware, and forget who I am or where I am at. I also ponder how strange life is and how it is definitely strange that we exist and are self aware. It is horrible and is freaking me out. I must say that I have been under the most stress that I have ever felt in my life for the past decade. I left the military because of this issue and after hearing stuff about the 2001 attacks that seemed like something out of a horror film. I take Prozac for depression, Xanax for anxiety (although my doctor is not nearly giving me enough) and have been on Seroquel before. (I stopped those, because I CANNOT stand the way they make me feel). If you can help it would be greatly appreciated because as we speak I am having immense trouble concentrating and am pondering why and how I came to be, and why our lives and looks are the way they are. I need to go to sleep, but I know what is coming. Please help if you can