What should I do if I feed too much

I am new to the lol for about 2 months and grew my level really fast. I started my ranked last week and started to feed really bad. It was 3/4/1 and my teammates started to swear at me even though it was only started for 8 mins. Some of them didn't even help me on team fight and I ended up 5/15/15. I know it's my problems but I wanna know what should I do if I feed like this because I played 51 ranked games and only won 17 of them.i fell from gold iv to bronze ii now and I am now feeling really desperate about this game. Can anyone tell me what should i do to atleast contribute to my teammates? Or just avoid feeding because I can do 14/2/7 with azir against lb but 2/8/3 in another game even against Annie. So I wanna know if there is any skills or tricks to avoid feeding. LoL sry about the teammates who did well but still lose.

Tl;dr : read the title