Playground, welcome to the community, sounds like you are in a tough situation. I'll relate a similar experience I had but it was not in a marriage but in a family business with a fleshly brother. My fleshly brother was constantly lying and unknown to me, was executing a unrelenting character assassination on me. Oh, he knew what he was doing. Some of his actions are nothing but evil. Proverbs 16: 27-27 says:
27 A worthless person concocts evil gossip[l]—
his lips are like a burning fire.
28 A deceitful man stirs dissension,
and anyone who gossips separates friends.
29 A violent man entices his companion
and leads him on a path that is not good.
After nearly five years of trying to work with him in a second generation family business, I was devastated when I found out the extent of his lying and his execution of my character. His mischief had been going on since Dad had died about five years before. The elders talked with me several times about allegations and I explained my point of view and tried to correct the fantasizing stories that my brother had but the elders would not believe me. They just looked at me like I was crazy.
I talked with a family counselor that was not a witness, and they skillfully and professionally explained the situation I was in. Basically, to make this short, I was dealing with a fleshly Witness brother who was a psychopath. The counselor indicated that there was little I could do, but protect myself and family by having no contact with them at all.
Here is a link you might find beneficial. http://psychopathvictims.com/psychopath/psychopathic-character-assassination.
So, There was nothing I could do to push back at the overwhelming false stories he had started about me and my wife, so we left our home of which I still love and started over. It was very costly financially to do this. Besides that, I lost all previous friends or people I thought were my friends, and god knows what was said after we left. But we are happy today and life is so peaceful without the cesspool of soap operas not only in my witness family but the congregation.
One final thought, a quote on the news tonight from Omar N. Bradley, "This is as true in everyday life as it is in battle: we are given one life and the decision is ours whether to wait for circumstances to make up our mind, or whether to act, and in acting, to live.
Read more at http://www.brainyquote.com/quotes/authors/o/omar_n_bradley.html#kgFAp6kEPmQfR0Fx.99
Again, welcome to JW.net