My first bitcoin buy was in 2016 september and I'm still regretting about that I did not sell my bitcoins at 20000$ still I believe that it will cross it's ath sometimes and that's why I hold my bitcoins.
This happens when the people become too greedy and cannot digest the profit that they are making it and still want to make more and more money in less time. It was clear indication at times that when things rise too fast in short time it will be falling in coming time and this had happened exactly the same way.
Thats true, u should start liquidating when there is a chance and diversify your funds.
I bought my 1st BTC in mid may-june 2017 when it was around 2k-3k $ and i have liquidated every month since then for my expenses and other stuff and i never regret