So, how do I carry silver

I have been generally getting better at not making stupid mistakes....but right now the problem is I see alot of people throw themselves into poor situations generally feeding a champ 3 or 4 kills early on snowballing them early and resulting in them continuing to kill other members of my team snowballing the rest of theirs...and generally preventing a push can be hard when they begin to hard push as 5 and fighting them is impossible Please don't troll, i'm asking for legit help