Not to be blunt, but you don't have the mechanical skill it takes to perform well with katarina, akali, etc. Stick to simpler champions for now. Jax, annie, master yi, and cho'gath are all strong picks that can brute force their way through the ranks. Try sticking to fewer champions, maybe 5 at most. And no more than 2 roles.
Die less, last hit minions more. That's all it takes to get out of bronze. It sounds oversimplified, but it's not. You're in the bottom 6% of the playerbase at the moment. Practice the fundamentals of staying alive in the game longer so you can impact it more and accruing more gold through minion waves. 15-20 cs is a kills worth of gold. You can win by simply being on the map for longer periods of times than the other inters players and having more items from farming.
There used to be a saying: "If you're not in platinum, play annie til you are."
Complex =/= strong | simple =/= weak.
If you want more advice and tips you can add me in game, but just keeping these things in mind will get you to silver V at least.