I have suffered from this many times over the past 7 years or so. I sold a portion of my btc at $13 as it had rocketed from $3 and much more recently, like you, I sold a portion during the final part of the bull run.
It’s easy to look back and say it was wrong as the price has continued to rise, but there really is no point in holding forever! At that time I needed the funds and i have bought back in several times, so overall I think I made the right decision!