I know how it is Bro. I was married to my ex for 17 yrs and we have 2 kids together. I found a way to shut her mouth. It may not be the coolest way to go nor am I proud of it, but sometimes you gotta do what you gotta do to protect yourself.
In the past few years together had gotten involved in the Swinging lifestyle and had taken some very hard core XXX pics and videos of her doing some very nasty stuff with other guys and women. I warned her if she didn't shut her fucking mouth they might just find there way on the Internet and in a few of her friend's emails as well as to various members of her family.
This would devastate her reputation professionally to say the least, not to mention the embarrassment and humiliation she'd experience because of it. I wouldn't really go through with it because I can't be that ruthless and heartless, after all she is the mother of my children, but she doesn't know that. There in lies the advantage.
It worked! She hasn't said another word to anyone else since and retracted what she told the people she had spoken to about my AAS usage explaining she was pissed at me and that she made it all up. I know because some of these people told me about it.
I'm sure in 11 yrs of marriage you must have something you can use against her to shut her up. Maybe not as extreme as my situation but put on your thinking cap. I bet you can come up with something she wouldn't like her friends, parents, coworkers etc. to know about her.
Like it or not, blackmail does work.