Take a deep breath. If you're on a losing streak, take a deep breath and do something else until you're in a better mood. Maybe even wait a day because we all have losing days. My best advise would honestly be to calm down and talk to your team mates. Like it or not, even in bronze, league is still a team game and you're unlikely to be able to solo carry with only a single division difference (high gold/low plat would be my best guess for being able to consistently solo carry but I could be wrong). Just talking to your team can go a long way, so long as you're nice about it. Keep them encouraged and give them tips IF you understand their position and how to improve that.
If you're looking to just climb period, there's also the given strategy. Pick a few easy to play champions for each row and really learn how to play them. Annie, lux, and amumu are all pretty good.