Why do some ADHD people take unavoidable failure so hard?

I was playing Overwatch about an hour ago, and was at the last objective with the entire enemy team dead bar one guy - a character named Wrecking Ball. After 20 solid seconds of shooting him, his team returned, killed us and won the match. It wasn't that I lost that bugged me. It was that I tried everything in my power to change the outcome and it remained exactly the same. I literally couldn't have done more. It was a numbers game that the character I was playing simply didn't have the damage necessary to kill him before his team arrived. I've had similar experiences with other things in my life, such as drawing. I like the idea in principal and in daydreams, but in practice, having to make thousands of mistakes in order to improve, with no way of circumventing or avoiding the failures, is enough to stop me from trying entirely. I've noticed that some ADHD people share these feelings toward inevitable or required failure. I've lost before, I've made mistakes before, but knowing that I was/am in a position that victory is impossible causes immense rage and, in some cases, depressive symptoms. Its a deeply frustrating feeling and I want to ask why you think this is? Also, if this reaction to unavoidable failure can be helped or even overcome, be it from meds, therapy or meditation, please let me know.