Can someone teach me to get passed "bad" teammates?

I am currently in the middle of another huge losing streak (right now 1-12 on 2 accounts/last one was 2-22). I have looked for help on reddit and summonerschool but nothing seems to help. cant tell if im tilted or not since I tend to play pretty well. Lately I've been playing mainly Supports since it was suggested that if you're struggling in game it may help to go into the support role, only problem is, that hasn't help the losing streak at all.

When i play other roles (mainly top or adc) i still do fine. some matchups are harder than others but for the most part I get kills push lanes team fight well. However, the problem is that most games I've been getting lately are decided really early bcuz the other lanes feed or the jg feeds and doesn't back up lanes that are struggling and we get steamrolled. Now i know this might be a tired concept, but i truly don't know how to turn these games around and i honestly don't know how to "get good" in situations like this.

I was hoping a higher elo player might be able to give me some tricks on how to over come this, or help give me an idea on how to Carry games like this. i know most ppl are gonna say it's something im not doing for the team, but when u go 9-6-5 and ur teammates combine for 43 deaths (18 by 20mins) im not sure what i should be doing to pull out a win.

thanks again in advance.