The loss of Abu Talib's protection was certainly demoralizing, if not detrimental to Muhammad's physical security. But returning home after one of his painfully violent revelatory experiences, or after suffering another indignity from the Quraysh--his head covered in dirt, his tunic defiled with blood--and not having Khadija there to wrap him in her cloak and hold him in her arms until the terror subsided must have been an unimaginable sorrow for the Prophet.