i need some advice please

just jungled udyr for around 15 games strait and ive been winning and climbing bronze pretty nicely then i get a guy who says jungle or feed then still manages to go 0-4 in 5 minutes and i cant pick up his slack because im sorak supporting my adc. now this isnt me complaining about elo hel cuz i know theres no such thing but can i get some help about trying to actually win games like this because whatever im doing is clearly not working?