The fact is, I am mentally ill. Not many people wish to admit it. But it has plagued me my whole life since I was a child. And continues to do. So, I might as well be open about it, since so many are not. Oh, don’t get me wrong. I am not going to stab a stranger, nor push somebody in front of a Tube train. I don’t think. Though I am often tempted. Aren’t we all? No, my form of mental illness takes a different, somewhat insidious form — and the main threat is to myself, you’ll be relieved to hear. But where did it start and how did it develop? Good question. I have been melancholic, full of self-doubt, hyper-sensitive to criticism, with no self-belief…