Dear Kate, now you know how I have been feeling for the last years. I finally got back what I believe to be the Labour Party when Corbyn was elected, and felt able to hold my head up again ands feel proud to be a member of the Labour Party. You say, “The grey chill of Corbynism frightens and disturbs me.” but as far as I am concerned “Corbynism” feels like a comfortable fire I am coming home to.
What are the “Labour values” that you cherish so dearly that Corbyn threatens? Trident Missiles? Extraordinary renditions? Sending British Troops to middle Eastern Countries? Imposing sanctions on benefit claimants? Work Capability Assessments? Benefit caps?
Time and time again during the Blair years I asked myself why I was in the Labour party. Or why Blair was in the Labour Party. 
Now Corbyn is leader I KNOW why I am in the Labour party. If you feel that the values Corbyn holds are not “true” Labour values you are entitled to your opinion, but you should stop imagining that many other people share your views.