You should always think positively. It could have turned out a lot worse. So, shake it off, add the experience/lesson to your memoir and next time you'll be much better prepared.
Also, to make you feel better, think how many others have been in your situation or even worse. These things can happen, all you can do it learn from it.
I have been in that situation, and a lot more. I could be 3+ million dollar rich right now, instead I have few thousand dollars, I had 50 bitcoins or so in my account back in the day, but this was very old days, instead I sold it when it reached a thousand dollars or so, used it to basically live a good life for about 2 years, and then I had nothing to show for but stuff in my house whereas if I kept it I would had a lot more.
However what did I do? Did I gave up? No, I just took that as a lesson and now I am growing my bitcoin amount, and since last year I have been getting richer thanks to this, still not giving up, I will do this until I know I have enough money to retire, and if bitcoin goes even higher than that, I will just say I have enough and will not care about anything else. A lesson learned and I will not do anything else.