When I first started to play Bleeding Edge I was expecting some toxicity. The best advice I can give is to not pay attention to them. Mute and report if necessary and do not reply to these people. They are not worth it.
I found myself entering games that were already in progress with one missing player on our team. Seriously, most of the time we win because I play as if nothing ever happened before I arrived. The way you play influences people to follow your lead. If you play the best you can, get objectives and get some kills, people will start to do the same and follow you in battle. (of course sometimes there is some people that do not change). Keep a positive mindset no matter what because it is you who truly matter in the end.
The other thing to always do is: Never leave a game even if you lose, do the best you can. Otherwise you will be placed with players that did the same in future games. (Some of the best thing that Ninja Theory has the power to do in order to counter toxicity)
Take good care of yourself and may your future games be better. 
and attract more people to play the game.