Whatever you do, here's one piece of advice: make sure that you contemplate this loss and how you got there. Stare it in the face. Think through your experience with this investment, and come to terms with the mistake you made. It will be uncomfortable; it will be painful. But if you accept that you made a mistake and find peace, you are much less likely to make the same mistake again. If you try to ignore it, play down it's importance, or blame someone/something else, you're much more likely to repeat it.