I actually have the opposite regret haha. I regret not sellin BTC at 20k usd
Current trend shows that your problem will be no more...very soon 
rocket is ready for the moon.About regrets regarding some altcoin selling, I happened to hold quite a lot of xrb, raiblocks at one time.
Distribution have ended and the price dropped so I have also entered in to sell-sell mode... what a mistake
...forget about a coin after selling...
100% agree, no other way to go but its sooo hard when you realise how much WAS at stake 