First and foremost, when the time comes take some fucking profits.
This is what I must regret.
If I had take 10-20% profil I would had recover almost all my investment and would be relaxed now. Possible buying more.
Never try that. Never sell until and unless they're worth enough to make you rich. That's what I've learned from an epic bull run of 2017. I was almost 90% out of crypto by August-November 2017 because I "took profits at 1.5x to 2x".
Maximize your greed, if you're ready to spend a few years in waiting.
I would say you are on the other side of the balance than most people here. I mean... who would take profits at a mere 2x? And *90%* out?
Many people here were at more than 20x profit (at ATH) and didn't take a cent out or just very little in proportion. Going all-in or all-out like that is just crazy gambling.
Actually, I was quite loaded with BTC even in 2015; I got those BTC mostly at $2xx. Keeping the psychological value of "$2xx" in mind, I started to take profits from $300+. Took profits at $300, then at $500, at $1000, more at $2000, and a lot more at ~$3500. By September 2017, I had almost "no BTC" left to sell (I was still quite heavy on alts though).
I must say, I stupidly underestimated bitcoin all that time, and had a completely messed up & crappy strategy. Oh well, whatever happened, can't be reversed anymore.