Crumpet - I am going through a similar thing with my witness family members and I'm not even df'd. Sometimes I just can't believe how heartless they seem, but I am learning that it is not about me. That is the hardest thing to do I think, after years of programming that tells you that you "deserve" the shunning and that they are doing it BECAUSE they love you.
Hang in there and try to spend time with positive people. We need to let go of the anger, the regrets, the resentment, the fear, and the guilt or we can't be happy. Looking from the outside in, we can see that THEY aren't a happy people. While they think (or SAY they think) that shunning is loving and they hope it pushes you to return. But we need to remember that the best "witness" we can give them is to be happy, let them see that our happiness is real and not dependent on the drone of the hive.
Trudy