I'll probably delete this comment later.

Honestly, if your self-respect is impenetrable, then no insult should matter to you. I was insulted by my own mother's reaction when I told her that I was gay. (I recovered from that situation effectively through a clever scheme.) But I wasn't devastated and had no hard feelings whatsoever. I just didn't care or feel despair. It wasn't in my control, and her, perhaps partially justifiable, inability to see reason and prioritise her affection for me wasn't in my control either. We are yet the only ones who can truly understand and judge ourselves since that knowledge is available only to ourselves. If you think that the insult was completely unfounded, then you shouldn't let it demoralise you. If you think that there was anything truthful in it, then accept the critism and recover yourself to decency by amending yourself. Terence, in his Adelphi, questions, rhetorically, whether a man should conceive in his mind or realise what is dearer than he is to himself. I think that since we are the only ones who can appreciate ourselves in true knowledge, we should do that to the best of our capacity and regard critism only when it is truthful. Dismay is natural, but don't let it engulf you.