I was plat 2 now stuck in plat 4 almost plat 5,what am i doing wrong?

So about 2 weeks ago i was platinum 2 and everything was going okay i went from g1 to plat 2 in 4 days.But now i just can't win any games anymore i went from plat 2 to plat 4 in 2 days.I try to stay positive in most of my games,but i'm bad at holding back if people rage at me for something.I currently main mid/adc most of the time i win my lane i farm well i get ahead on my enemy,but then at mid/late game people just start doing stupid plays.Last game i was playing Cassiopeia mid i think i was 6/1 at laning phase and our top laner was vladimir which was building full apeven tho we told him to buy some tanky items because hes gonna get bursted down but he just ignored us and flamedand form 1 bad call and him and adc getting bursted down in tf we lost the game.Then 2 games ago i was playing adc ezreal was 2/1 in laning phase everythng was going great untill later where our junglervi pinged to go on baron 2 of my teammates followed her and they got 3 man killed at baroneveryone was up in enemy team so baron call was really stupidso they died enemy team got baron and they pushed mid we didnt lose yet but we couldn't win anymore since vi started flaming everyone in our team for not following her and because she taught baron call was good. I really don't know what to do to actually anymore i try to improve and fix mistakes i did every game,i dont flame anymore the way i used to,i try to focus as much as i can but i just cant win anymore,does anyone have an advice on how what i could do? Thank you for future responds