Here's something you don't see traders post very often - an actual losing day! While a lot of people try to dance around it the reality is that as a trader you will have losing trades and sometimes you will even have days where you ultimately end up a few points in the red. It's pretty much inevitable unless you're trading dozens of times a day to ensure your edge plays out.
By itself a losing day isn't necessarily anything to get upset about. You can trade exceptionally well and do everything according to your plan and some days the cards just don't go your way. That's all part of operating on probabilities and even trading strategies that win 90%+ of the time can string a few losses together.
The thing to keep in mind however is that if you know your edge is strong and will continue to play out in the future then there's nothing wrong with that single day's outcome. That's why I evaluate my performance based on if I followed my trading plan and how well I managed my trades rather than the end result. I know if I focus on the process then the results are inevitable, even if they might be elusive for a day.