I have an extremely low win rate (35%) but I have no clue of what i'm doing wrong

Last season I went from bronze 2 to gold 5 in a month, with a really good win rate (56%), but now I feel stuck, I can't carry, every game feel the same, my mmr is garbage right now. I don't know what i'm doing wrong and I want to improve, I never flame or troll, I always try to be polite and positive, but this doesn't really help, any advice?that's my opgg: https://ift.tt/2Kssfn8 only thing I noticed is that I die too much, but I can't really avoid it since enemies are always so fed they can easily dive and kill everyone, can you give me some tips to stop dying?p.s. sorry for my poor english, i'm italian