Diamond made me quit the game

I've been 'hardstuck' diamond for the past 3 years. For the past 3 years i've been bashing my head against the keyboard trying to understand that stupid place and i still don't get it. This season i got both my accounts to diamond 4 and the same thing happened to them. You climb and climb and all of a sudden ,after a lost game riot just puts you every game with people that are on loss streaks/tilted/boosted/bad/flaming. It's wierd that this season it happened on both of my accounts ,at the same point where I was on either of them. I play supp/adc and i've come to the realization that these roles matter in this elo as much as the health of this game matters to Riot. But I won't swap to jungle or top after 5 years of bottom lane is not the hypercarry role it used to be without having a good premade. My advice ,if you're new and trying to climb ,pick up jungle or top ,even mid and spam champs that one shot things (rengar,camille,jax,graves,ekko,talyah,irelia). And a lot of people will jump and tell me that Kai'sa is busted and that adc meta is good and i can agree with you on that ,but the important part is that you have to get a certain item threshhold which will never happen if you're whole map has 0 pressure and you keep getting 4 man dove with no one responding. If you try to tell people to come help you ,they say you're flaming. There's no win condition. I played to improve but I played the wrong role. Thanks Obama.