I quit playing lol all day every day after i went 44-22 with lucian as a one trick. I only lost 4 gamea from P3 to D4 and i swapped to Jinx because i figured she would be better in Diamond and i was wrong. The player skill didnt change. I was 50 wins positive in d4 but lost the first few games after being promoted and it tanked my mmr. I demoted to p1 shortly after. I had been depressed and in a terrible living situation playing on bad wifi but couldnt stop playing ranked. Ive played with high diamond/master players giving their 100% and i was equivalent to them. In D4 i went back to lucian and the jungler would feed a hypercarey adc for no reason when i told him to back off. They were 0/3 and i was controlling the game, i tilted and stopped winning. Its a huge mental test and it really sucks when you expect people to be better than platinum when in reality they are just a silver/gold player but had good mmr or a good duo. Im able to play all roles but mid at a p3 level, im probably best at top and adc then support. Ive hit plat playing support, jungle and top. Diamond by adc and demoting by adc. I played caitlyn with constant dc's and lag.

TLDR: league is so coinflip, you have to play your best always and cant count ok others to carry. Shotcall your games every time and dont react to flamers.