I've been playing this game for 10 years.
I've dealt with everything from players wishing cancer on me and all my families, to where they simply wish me dead because I didn't pick a tank, or told me to take my own life because I didn't pick ignite to even where they wanted my address so they can murder in my sleep.
I've dealt with players intentionally fed because I said "Gj, you got em" and they took it completely wrong and muted me before I could explain to them what I meant by it. I had players who intentionally fed because their support had Targon and told them not to take the CS because they wanted to their CS score to be top notch. I had 9 players making insulting me due to my art hobby and harassed me nonstop on personal pages I had to delete, telling me how terrible it is and that I shouldn't proceed to do it anymore.
I've dealt with a lot in this game. But I've always found the mute function work in my favor.
I've learned not to share anything personal about myself, and I've been stuck in a tier I can't get out of. Not that it's my team faults.
It's just I've come to terms that it's where I belong. But I can't complain, I still get rewards if I work for it.
Just use the mute function. Truly, it does help.
I simply learned just to try and enjoy the game itself and do my best. Because reaching a certain tier doesn't mean anything really.