Hey, nice Op, seems like youre doing pretty solid despite the anger lol :P

One thing I would suggest for coolers like the 55 vs KK hand is think about what you would have done in the other players position. If I were the villain i would stack off verse you with kk all day everyday, I rarely made big folds in 10$NL when I was playing it. Since you would have played it the same way just dont let it bug you at all, EV evens out over time and in situations of AA/KK verse set mining it is likely two decent $10NL players are just stacking off every time the set hits because there are too many fish at $10nl to make folding KK every time an op shows a set like line +EV...

I struggle with the same things as you with anger about the beats and I tilt some of the time when they happen, lately Ive been taking breaks after -3 buyins and really trying to not be results oriented, its a never ending battle, gl!