What is going on with me?!?

In 2009 i was diagnosed with depression after battling with being bullied and my mum and dad separating from each other. I had been self harming for months and not eating for months too. I was given anti depressants that i used for one week until i went to see a psychiatrist who took them off me. After seeing a psychiatrist for a few months i thought i was feeling better and left. I still felt depressed and carried on sleeping the days away, feeling depressed, self harming and not eating. When it came to January of 2010 i completely changed, i was either not sleeping at all for or having an hours sleep and feeling fine when i woke up. I went out drinking with friends every night until i passed out and even started smoking. I felt great, life felt amazing, i was getting into relationships which ended up turning sour after a few months. I was being reckless i just didn't know it until september hit and i was depressed for months yet again. Now its got to today and im still constantly up and down. One day im talking so fast no one can keep up with me, i have so many ideas my mind cannot keep up, i think i have special powers, i get so paranoid i think people are stalking me or that my boyfriend is playing away and i get so angry i physically hurt my boyfriend and then a few days later im constantly sleeping, feeling so sad and unable to enjoy anything, some days i cant even walk to the bathroom i feel so depressed. I have also developed an eating disorder. After years of being so skinny i cant stand to see myself with any weight on my stomach anymore so i either fast or make myself throw up. My mood swings are really severe and they have been getting closer and closer together. Any suggestions on what could be wrong? I dint even feel human anymore! :(