I guess this is something I need to address myself as well. I am extremely competitive and I can not stand it when I don't show the skill I know I have. I could 20-30k+ ranks over what I am now but I make such dumb errors. Shit misses, laptop lag spikes, and about 14 songs I would've FCed with 1 slider break. It's so infuriating. I have completely broken 1 mouse and 2 pairs of headphones over this game. That's not as bad as when I was in high school, but still, not good. I know I shouldn't and I'll regret it afterwards. I just remember the money I have to spend if I do it.
In your case, I suggest what I do, just sigh and realize it's a game and that after awhile you'll get it. I feel like I'm improving every day with stuff I couldn't do last week. Losing or making a mistake is all a part of getting better at the game.