The lack of sympathy is understandable, though I do think becoming depressed after a huge success is probably very common. You've spent so much of your waking life for years working towards a goal and then you attain it, and maybe that success no longer needs your hard work, so there's a massive vacuum in your life. Obviously there's more to life than business success and it'll take time to find your purpose again, but that come down, I think, is natural.

It reminds me of the article about one of the co-founders of RxBar and how he was finding it hard to search for meaning after they sold their company for hundreds of millions. It was posted here years ago: https://news.ycombinator.com/item?id=21138106