As a support main, I feel your pain. Jung/Supp are the hardest ones to carry from, imo.
One thing is to actually avoid the best laner (fizz in this case) and try to get the other ones rolling. At some point hopefully your team would have caught up to the enemy in farm or something.
Try to stick as a singular group and hope for the 4v5 as well.
Ward for your lanes. If you know they have a roaming mid, keep both death trap river bushs warded so that you know which lane he'll be roaming to. Or keep skuttle control.
Yes, sometimes you just have to wait for the enemy to make a mistake (cough coast baron calls cough)
You can also try carry style junglers. For example, Sej and Vi if they're up. The lesser banned Xin can make your team snowball early. Zac and Amumu are great for the tank meta that's up now, and I feel like their cc is a little easier to land, and affects more people on the enemies team.
Not saying cho isn't fantabulous. Just that he can't solo carry as hard as others.
And you know. The usual. Not all games are winnable. What I try and do is look at what could I have done differently and learn from my own mistakes. Because odds are, those people? I'm probably not playing with them again.