When I was 10 I went to the Drakensberg Boys Choir School, which is this idyllic Harry Potter-esque music boarding school in the mountains in South Africa, and that's when everything started to change for me and I realised that music is my thing.
Reassurance can actually exacerbate anxiety: when you reassure your friend that the worst-case scenario he fears probably won't occur, you inadvertently reinforce his belief that it would be catastrophic if it did. You are tightening the coil of his anxiety, not loosening it. All to often, the Stoics point out, things will not turn out for the best.