My marriage was really strained while I was forcing myself to attend after I learned the TTATT. Once I stopped it wasn't long before the kids stopped too. Our marriage improved once we both got used to our new situation. It's not perfect and I will come on here and vent from time to time but all in all I'm happy.
My advice, as worthless as it is, would be to stop attending meetings, don't frustrate her with telling her how bad the WTS is and back the kids up in not going as well. I decided very early that if my leaving the witnesses and supporting my kids leaving the witnesses were a marriage-breaker then so be it. In my case my marriage survived, many don't.