I have always thought that selling at a loss is a serious mistake. I understand that people who sell at a loss may think that by selling they will not lose everything, and that they will be able to recover at least part of their investment. But it is just as important to know how to wait as it is to know which project is the most appropriate, that's why there are people who never make money, due to lack of patience.
Choosing the right project (in this case Bitcoin) and knowing how to wait after making the investment are the basic and most important pillars, but not only when we talk about cryptocurrencies, but when we talk about any type of investment in any industry. Each factor must be a complement to the other to be successful.