Suicidal Possession?

First off, let me first start off by saying I have no history of mental illness. I was a very happy girl growing up. A little bit of stubborn temper, but that is because I am Russian. In the 7th grade year of October, I was watching a documentary called “30 Even Scarier Movie Moments” on Bravo. One of the movies mentioned was “The Exorcism of Emily Rose”. I grew very interested.  I found the book that the director based the movie on. It is called “The Exorcism of Anneliese Michel”. It sparked my interest on demonology and the paranormal. I started watching movies involving those subjects, particularly with exorcisms. I grew obsessed. I even learned my cursing from the “The Exorcist”. A few months later, I grew depressed and feeling that I was alone in the world. Over my high school years, as each passing day went by, I grew so depressed and angry. I have no reason to be angry. So for no reason. I was so angry and hostile towards anyone who came near me.  I started to self-harm. But not cutting. It was to dig my nails in my anal area and bleed myself. I still do it to this day. I am a catholic. Normally, I was excited to go to church and sing the choir songs. But now, it is like every time I walk near the church I get a head ache. When I walk in, after a minute, I grow sick. I found the songs and prayers annoying. Every time people talk of god, I get so angry; I start cursing his name and tell people that god enjoys their suffering. One Monday, I was in the bathtub, all of a sudden I got a very strong urge to drown myself. I was given very clear images in my head, of reasons to kill myself. I had my head under for 30 seconds, when I freaked out. Because I was so anti-social and depressed, my mom then sent me to a therapeutic boarding school in Michigan. I was there for a year. My thoughts grew more suicidal and angry. Thoughts came in my head, that I am alone; god has abandoned me because of my obsessions, that I have no purpose, no friends, and no loved ones. I am now in college. I am uneasy around people. I grow anxiety every time someone walks in the room. And by now, my anger and depression is so high, I don’t want to live like at all. One night of last year in November of 2011, I was taking my medication, two pills, and I get the sudden urge to take all of the pills of my medication. Thoughts of no purpose of living, every person one the planet hates me, and a lot of anger towards god. I was about to take them, when my roommate comes in and freaks out. Police came, went to a mental hospital for six hours. People don’t get out until after 42 hours. I made up a lie to make the staff there think I was sane, and trying to get attention. It is now January, and I grow worse by the hour. I don’t want to die! But I do! Is it possible, that there are demons that influence you to believe you are so miserable, that you feel hopeless and want to die? It doesn’t possess me, but it draws me towards the devil? Please help me!!!!