That was very bad time for me, when i sold out my Bitcoin. When bitcoin price was 9k+ usd, then i sold out my all Holding Satoshi for my personal problem. But now current price of per Bitcoin is 41k+ usd.
You sold your bitcoin for personal reasons. Depending on what that problem actually is, think about it— You might've been in a far worse situation right now if you didn't sell your bitcoin for well needed cash. (unless of course, your "personal problem" is something trivial)
That's very right. That's why even if I sold my btc before, I am not regretting as I sold it at that time because I needed the money. So if the OP sold his because of his personal needs, then I guess, there's nothing to regret. Just consider the situation that you will be in if you haven't done that before. This is how I think about the situation, if you will regret for the times you sold your satoshis, what will be your situation right now? Just move forward and don't regret the past.