This is a common mistake, as far as I see. Why hold further if you see that the assets you're holding are dying? Just sell now, while they cost at least something, or you'll just lose it all. It's better to save at least some money an get back 20% of invested that lose everything.
Selling is not something bad, it's not a weekness, betrayal or renunciation. You'll not leave the market selling your coins, instead of it you'll get an opportunity to buy back even deeper and then continue holding hard.