Should I see a psychiatrist, how easy is it to see one?

[Joseph]

I'm feeling not myself anymore, I want to just by analysed and have my mind set at ease. I walk about in public, sometimes feeling in a world of my own, and often wouldn't feel weird if I done silly things, because I'm "not exactly there". I don't know if this is normal, but I don't hear voices or anything like that, I just feel not so normal. I was drinking one night and message a guy on facebook who bullied me in my youth, and i give him a death threat, was a horrible mistake and it's lowered my self esteem. My head was gone that night, I can't remember much, but my dad said it was scary and that I was acting strange, I was furious. I was on Sertraline 50mg for about 4 months, slowly cutting down after that drinking period that night, I'm now taking half of one a day. I was also seeing a counselor during my medication period. I have this homicidal fantasy I can't get out of my head, it's making me feel evil and insane, but I'm not, generally I'm a nice young man, but due to the media, all these shootings you hear in america, it's getting to my head sometimes, and i feel guilty for looking into the stories. Please help, I want to start feeling innocent and normal again, I have a lot on my mind and don't have friends, I'm quite anti-social.
I'm 19.