This is what I'm here to hear.
You are right - I cant get custody....trust me, in the UK it is very hard for the man to get anything unless the woman is in a shocking state. I have friends who tried with their drunk wives who were far worse than mine (drink driving, waking up in the street) and they failed.
But to move on and leave them is also wrong. I only moved out so she could get straight - if she isnt going to bother I might as well go back and be there for them.
Great advice, thank you. (slap in the face i needed)