Phew I didn't insult you
Two things today - firstly, even though I left my ex p it took me years to get my confidence and self esteem back. one thing that helped was a self help assertiveness tape that someone lent me. It sounds pathetic but it really helped.
Every time your h does something like that coke incident or talking down to you, you just repeat to yourself
'No matter what you do or say to me, I am still a worthwhile person'.
Then, the bit that really really helped me through that horrible day when I knew I was going, but he'd been threatening suicide etc (I actually looked at him and thought, oh good that would save me a lot of hassle if you top yourself ), is that YOU are not responsible for someone else's feelings. You have to act in the way thats best for yourself, and they choose how they react. So if he goes mad, suicidal, begging, upset etc, he has chosen to deal with your leaving in a particular way and its up to him to deal with that, not up to you do do anything detrimental to yourself in order to make him 'feel better'.
Secondly, this wedding. He is keen to take the children so that he can show a fab-father-adoring-kids front to his family. He is not bothered whether you come, because then he can put on some long suffering husband act about you being an agoraphobic nutcase to his family and get their sympathy.
So, I say to you, STARSNSTRIPES that you should be long gone before that wedding, take the kids with you, and not give a shit whether he is shown up at not having his kids present at his brothers wedding. Because he's never given a shit about whether you are shown up to anyone through his behaviour has he? Taxi drivers, neighbours, his family etc etc.
Let him go to that wedding on his own, and if you are gone by then I can assure you, you really won't worry about the wedding. Once you've gone it will be like a curtain drops and regarding your home and husband it will be like someone told you that you were once married to him. There will be no emotional tie at all once you've gone, just relief. But you have to GO!!!