I can't take it anymore

I started playing LOL at the beggining of this year and started going rankeds last month, I started as an hopeful brazilian JG who reached this week bronze 2. I was set in going to the next elo, but suddenly I had a 8 FUCKING GAMES losing streak where at THREE of these matches one of my teanmates were AFK, and other THREE matches there was someone in my team with the KDA of 1.0 or less and now I'm back at bronze 4.

HOW THE BLOODY HELL do I escape this elo? Is it luck? Get good? Duo? Turning off my PC? Uninstalling LOL?

Now seriously, can someone give me some tips on how to win rankeds and getting to the next elo? And also, does it get better later in the game?