Minus the anger, I'm have similar thoughts. No doubt you will be told what I have been told by most on here- go to your GP, get help.
If you truly want to do these things, then my advice to you is too keep yourself busy. 'Idle hands are the devils playground' and all that other pointless bollocks. Yeah, distract yourself with hobbies etc. People that I have spoken to in this situation find that their thoughts are at their worst when they are bored. Unfortunately for me- I am constantly bored, but hey, it might work for you.
*EDIT* Oh, and failing that- think of how much prison would really suck. That works for me.