Someone usually comes along and says s 18 is a very serious charge and you can get life imprisonment for it. Ignore them .It is strictly correct but nonsense even in cases of gangs maiming people for life, so forget that. I am betting that they'll take a plea to a lesser charge if indeed they do charge s 18. Drunken nights can end in murder, so being drunk doesn't help, in that it doesn't provide a defence, but with someone like you, no previous, a one off incident of loss of self-control, possibly some provocation (Who knows? You may not because you were drunk, but it may be discernible from the papers and there must have been something to set you off), and something totally out of character, should keep you on the outside after sentence. I'd expect so. Don't pack a toothbrush just yet !