I am at my wits end, wife is impossible, wot can I do?

Sounds to me as though you have really tried, and that she is very manipulative, I'm sure that you probably tried to ride it out for the children. What good are you to them if she continues to over run you, you are the man of the house. I hate to say it, but, I'd leave and stay gone. Do not get the church involved, they will only lay a guilt trip on you. Leave, move to the beach, get visitation rights, be prepared to pay child support, you got a long road ahead of you, you may as well be somewhere where you can enjoy your life. Those children are going to need you later on in life. Good Luck