My portfolio did well, I am up 35%.
I sold ETH's because the market started to crash when covid hit and I did not think it would rise again. I still cannot justify the rise of ETH and BTC to the levels it is now.
Regardless, I look back at my 35% gains, and I see what I could have had if I didn't sell.
How do I minimize my regret? I feel terrible, I could have changed the life of my parents and family if I were to sell 300 ETHS today.
I feel like I'll never get another opportunity to make this money again and I feel like a loser.
edit: (I had bought ETH in total for at most 10-15k USD many years ago by dollar cost averaging up)
However, you should use this as a learning opportunity. Think back to your decision and try to objectively review your decision making process. Why did you make that decision? What information did you take into account? What other factors were at play?
Knowing what you know now, not counting the price, will you still make the same decision? Why or why not? You said you cannot explain the BTC and ETH price increases. Try to. Why do you think that happened? Could you have predicted those factors better?
Believe it or not, you will face this kind of situation again but you will be better prepared for it if you do some decision analysis.
Also, everyone that sold when you did are also feeling regret of what could have been. It's a fantasy, no one knows the future.
There are better ways to use your time than to regret a fantasy.
Be careful with this. Your beliefs become your reality and your reality is based on your beliefs.
And half a mill is not alot of money if you're in the US. Try to focus your energies on building a company that does that in profit every single month, rather than waiting for some lucky break.
My $0.02