I think it's natural for people to feel regret knowing that they could have that "thing" It can be a profit, it can be an item, or whatever a person may want. I don't think you would be regretting anymore if the price went up again but that's just what it means, you need to be prepared and accept your decisions no matter what happens.
Yes. You need to get over it before it crashes your interest in the crypto you already own. You know this market works in cycles and you have to understand this as well that we have been through so many ups and down through these years. What I want you to understand is that you can get the value of your portfolio replicated several times upon the arrival of another boom so be optimistic and stay hopeful.
People all over the world make mistakes, and it's not just one person. Learning how to overcome the right way would lead you to a better life. I suggest that you know what to do with certain market conditions and having a non-stop market makes it harder to grasp but definitely can be studied and mastered. I hope it's that easy to say "replicated," did you mean double? If passionate people are surrounding the market and using the actual cryptocurrency it wouldn't be that hard.