I have been noticing that I've been losing a lot of games recently (not ranked mind you). I wondered why, then I realized that 85% of my games went the same way: I would get fed as most of my allies would feed (not all though), I gank to try and help, but my ally barges into the enemy like Rambo and dies before I can help him, the laning phase ends so we team fight and lose (I can't 1v5 the whole team), I tell them to push while we have a chance, they worry we'll die and say no, then we lose. I ususally have a score of about 12/4/6 or something. I know that isn't amazing, but the rest of my team (mostly) has negative scores like 3/7/2. So here's my question: is there something I should do, and is their a champion that once fed, can carry the whole team? I have over 9,000 IP, so price doesn't matter. Please comment to help me on what I should do. 

P.S. Thanks for all the comments. The point of this post is to see which champions have the biggest team fight presence and help their team the most.