When you play a long ladder session, you can sometimes get very frustrated about the losses and long games and late game losses and early game cheeses and everything else that went wrong. Sometimes there will only be one or two games that stick with you; sometimes it will be up to 10. However, you need to put all of that behind you and focus on improvement.
Ignore the late game, ignore the bad choices you might have made in that one base trade, and ignore the loss to the 6pool because you were alt-tabbed and didn’t see it coming. Instead, start with something simple and focus on improving it. It may be as simple as remember constant SCV production in the first 10 minutes of the game in order to hit that benchmark of 50 SCVs by 10 minutes. It may be something as complicated as remembering to counter attack Terran’s 3rd with 20 Speedlings as soon as you spot the Terran army move out to the left hand side of the map.
Just make sure that every game you play, you take a deep breath, put the previous games behind you, and remember to focus on improving that one aspect of your play. This way, ladder sessions will not only be a lot less stressful, but also will always be considered wins in their own right. Every ladder session where you successfully improve one aspect of your game, even if you technically lose all 10 games in a row, can be considered a win in terms of improving your game. You’ll be happier, less stressful, and improving faster if you approach ladder sessions with this mentality, I guarantee it.