I can't sleep consantrate or do anything
24/7 I'm replaying my life conversations and thinking what I should have done or said I just can't do anything without feeling misrable
Of all my life always thinking what I should have said or done
I'm so misrable and now if I just hear one little sound I get so angry I can't live like this *** help everything around me irratates me
I'm almost 14 if that helps

I feel you my friend, you sound like your going through what I do almost every night before bed. I avoid even trying to sleep now, because I'm afraid of what thoughts attack me as I lay my head on the pillow. I have a bad habit of distracting myself up to the very last minute I can stay awake and then passing out from exhaustion. I would feel horrible if someone at your young an age has to deal with that for longer than what you have already... You must feel like you aren't 14, and are in fact years older in the head... replaying and thinking all your life events and wondering the other outcomes. It becomes an obsession almost, I think about things that could happen and all the ways those could turn out... my mind might stray to the negative side and so I end up not bothering to even try and I've successfully talked myself out of something.
Please find someone to talk too about this, be it best friend your mum a school counselor. Your words "i can't live like this" are scary to hear, you can pull through this!
The obessing thoughts are hard to break, but you sort of have to get yourself out of the habit of thinking about yourself and what happened all the time. It sounds weird, and when I had someone say that to me recently I felt horrible... I realized how much I do think about myself my life what I do how I do it how often what where blah! It's a tumbling mess of thoughts all about me and my situations and how I could do it better, or what I should have done. I don't like myself, so why am I thinking about myself all the time? Everyday now I am trying to pick a topic I want to sort of zone out on, yesterday I looked up what music programs I want to start learning to use and make music with... the night before I watched videos of kittens all day =/ This is a poor way to handle it, but for now I am sort of keeping my mind off myself, and therefore slowing the thoughts down that drive me nuts...
And wow, you look for an answer and I end up telling you all about my problems. I'm sorry... I shouldn't even post this but maybe there is some relevant information in here for you.. I hope it's not a waste of time. I wish you luck and hope you can get some sleep soon, Talk to your doctor even, he is bound by confidentiality and couldn't tell your parents unless it's horribly life threatening I believe. In that case though it might be best if you had there support then.. Talking to someone in the long run will help you I swear.
Goodluck! And sorry if this is useless and doesn't help you ):

Well sorry but it diddnt help I can't talk to anybody any low sound makes me angry is hard to talk to peole its hard to do anything

In another way it helps to see that I'm not the only one