All of us are going to feel sad when we are going to lose in trading. It's a normal feeling and you are not a person if you can't feel sorry and regret when you are losing. But with those loses it is teaching us on how to become stronger. With the lesson I learned, I started to hold for a longer term because I can see it's more promising.
But also lose is a great teacher since it teaches us on how to act correctly so next time around we will not lose from the same error on our trades. But actually those heavy losses always occuring on certain dumps where people cannot take to hold and believe on the coin that they are beholding.