But what is the actual reason behind this vast fall?
It can be this incident.
Coinrail Exchange Hacked, Loses Possibly $40 Million in CryptosMy friends are laughing at me, who sold their bitcoin when it was 14K USD! That time I told them you guys are doing wrong, Hold your bitcoin, Bitcoin Price will rise again. And now I am regretting really

What you feeling isn't different to most of the holders here.
Let them laugh for now if they have sold at $14,000 and if they are thinking that they are in profit now. Just don't think about them, focus on your holding.