Great and how are you supposed to do that?
People say that you can get into higher ranks by just playing well. And I'm sure that's true, but I cannot play so good that I can compensate for a person going Torb on attack or Widowmaker when they can't hit shit or going in with no DPS or otherwise making such catastrophically bad decisions that they're either throwing or playing so badly that it amounts to the same thing. And that's when they aren't leaving.
Sometimes I get lucky and it's the other team that gets the shitty teammates that make these game ruining picks (which isn't good. I don't have fun when I'm winning because a douchebag is sticking to Torb on KotH), but usually, it's on my side.
Near the end of the season, it's worse than ever, and I'm about to dip down into silver where players do this with more frequency.
Just fuck my life when it comes to this game.
I'm going to be perfectly blunt, don't take offense to any of this.
1.) As blues suggested, take a break from the game or at least comp until next season. I tilted so badly one time in S2 that I was affected IRL (it was with one of my friends). I knew I had to take a break for a bit and come back with a fresh mind set. Haven't got anywhere near as tilted since then, I even reached a new career high because I changed my attitude (didn't even get to diamond S2).
2.) Most of your posts are about your team not performing well and the other team just outplays yours. Are you sure you're playing as well as you think you are? Have you looked at VOD's of yourself playing the game, because I guarantee you that you're probably making as much mistakes as your team is, otherwise you would be climbing. I've had a lot of experience in low plat in prior seasons, I can straight up tell you that the other team is just as uncoordinated as yours, it's just a matter of who setups up the better plays and actually capitalizes.
3.) I'm not sure what you're expecting in plat or above, but the truth is: you're still going to have shitty teammates, there are still throwers, there are far more toxic people in diamond, and there's still widow/hanzo/torb mains. The only difference is the level of play starts to slowly increase (people get better at positioning, staying with team, playing their role etc etc).
4.) Are you in the right role? It sounds like you're mainly DPS, more specifically a tracer main which is fine. But if you're not killing the healers/DPS even if they're playing amazing as a team, then you're not doing your job. Gold elims/Gold damage doesn't matter (this should be a given to have one of these as DPS), if you can't kill your high priority targets, you're about as useless as the torb/widow/hanzo mains everyone complains about. There's nothing wrong with switching roles and doing heals/tanks as that's a luxury in gold. I'm not sure about your skill levels in other characters or roles but a good tank player can carry/turn the tide just as much as a DPS can. Tanks players are the ones who can setup big plays when the DPS can't.
TL;DR Take a break, review your VOD's, work on your positioning/game sense/mechanical skill/job role and you'll see yourself climbing. Don't focus on the SR numbers, people get too hung up on that. I've lost 200+ before it's no big deal, you'll either regain it back by making improvements in your game play (the only constant in all your games) or stay stuck in the same levels blaming your team.