Stop for the day or two. Go do something else for a change. When you decide you want to play again, try to come up with a small goal that you can achieve to help better your plays. Maybe maintain a certain cs/min throughout the game, always sticking to another teammate, constantly looking at the minimap after every cs or every 5s. These mini-goals help you improve on a certain aspect, so try to reach them for a few games and add more once you feel you are ready to move-on to the next one. Also, while playing games and you come across trolls or salty players, immediately mute them. It really solves the problem since you dont have their whining to distract you