How To Come Back From Falling Behind As A Team?

I'm stuck in bronze, and given that it's bronze league it feels like there's an overwhelming chance something will go wrong in the early-game. Now I'm not one to sit here and pretend i'm perfect, I know i'm not, and sometimes I can have a REALLY bad laning phase. Sometimes my performance is lane leads to me getting a bunch of early kills, or sometimes it's sorta a stalemate and neither side gets much of an advantage. But for those games where I'm doing average or well, in about 90% of my ranked games at least 1 lane is losing hard. Maybe it's top or mid, sometimes it's even our jungler who's getting a bunch of unnecessary deaths. Long story short, the game snowballs and eventually we just lose because the enemy team has a big lead, or maybe they just have a single powerful carry that got fed early.

I ADC main tristana, and I have no idea how to get around this and "carry the game" for my team. Eventually the enemy team starts wondering all over the map, so there's a good chance of getting picked off if you try to push in 1's or 2's, because you never know when the ENTIRE enemy team jumps out of a bush and ganks you. Your team is forced to teak fights that favor the enemy, and you can't really farm once the creeps move far enough out on the map. It just feels so hopeless and I don't know how to get around it -__-