I think that you can mark a point for yourself when you need to cash out but till that moment you can just keep on holding. Recently I decided to cash out a small part of my portfolio when BTC was at $35k but now I regret my decision so hard because BTC has reached a 37k just in a few hours after it

If you trade you can set the lowest point for yourself and open some stop-loss orders and minimize the risk of losing funds. I'm pretty sure that BTC can easily reach a 40k mark by the end of this week so there is nothing wrong with holding your bitcoin until that moment at least.