some things that i have learned getting through same elo as you is
1. never play alone, get a good duo partner, he dont have to be your friend, or be friendly, as long as he makes impact on the game, it is good. ( ap mid and jungler duo is best choice)
2. do not rely on anyone except your duo partner. ( there are so many times where i expect my teammate do a certain thing, and they do not even think about it, i still do this mistake today which make me want to hit my head on the wall ahah)
3. play character you are really good, always try to do maximum, carry every game.
4. play safe, it is better to be smart and play safe, then run for a tempting kill and die in process, you never know how the fight can turn around, so you better stay alive. (example: a couple of days ago i played my diana, and 2 games i got quadra, and i could get penta, but i was too low, and no matter how tempting it was i juked that last enemy and let my teammates safely kill him/her)
5. if you get to choose between a kill and turret (inhibitor), always go for objectives. if you kill an enemy he will respawn in around 30 seconds, but inhibitor will take way longer.
6. real counters do not exist until 1600elo, but still, do not get katarina at first pick and get yourself countered by diana who will not even let you to use your ultimate. be smart, pick for somebody else, and swap.
7. and last but not least, never say "oh elo hell, i noobs, blablabla". this will make you rage even more, and will not benefit you at all. Always blame yourself first, think what you could have done better, admitting your mistakes is a first step. You have to have a certain mentality, approach. You cannot make mistakes at all, because even 1 mistake can decide a game. (example, it was around 30 min, we had a teamfight near baron, i was pretty fed as ap carry, our adc was strong too, but, our team failed to reach enemy ezreal in fight, so he avoided all the damage, so our skarner run to chase ezreal miles away from the teamfights, not being able to kill ezreal, and leaving his ap and ad carry melting down to enemy rengar leona, and other assasin. we were winning whole game, then 1 mistake lead us to lose 2 more teamfights, because team just started to throw after that, and we lost the game)
Sorry if i have some grammar mistakes
From Russia With Love, IntMakaZ.