To be honest, I wouldn't even worry about win rate if you're not even level 30. Objectives are usually such a low priority that it turns into a Team Deathmatch of who can screw up a team fight first 40 minutes into the game.
That being said; If you're playing on tilt (basically means performing worse than you normally would) due to a losing streak, or anything really, it's best to take a break from playing for a bit. Maybe a day or so, depending on the person. Once you've relaxed and are ready to get back in there, make sure you're in the right mindset and thinking productively. If you go into a game thinking you're going to lose, chances are you'll play like it and lose as is the self-fulfilling prophecy mindset. Keep mental notes of both what you did wrong and right. If you die or something goes amiss, instead of thinking "Man I wish my team were better" or "Why didn't he do that instead?" try thoughts like "How could I have played that better?" or "What could I have done to prevent that from happening?". The former of the two is unproductive and toxic, and will hinder you from improving. Regardless of what your team does, you'll never see them again (or rarely) so what they could've done better is a useless mental note for you. The latter of two is productive, as reflecting on how you can improve will allow you to become better and win more games despite how your team plays. Keep in mind that some games you just won't win because the enemy team played better. Happens to everyone. Don't sulk over it. It's also important to make mental notes of the good things you did, so you know to keep doing them. Enforcing good alongside working on bad is what keeps a healthy, mental balance. Too much bad and you end up on tilt. Too much good and you start thinking "I deserve challenjor I dont belong here".
