Going positive alone isn't going to get you out of low-elo, if it was that easy we'd all be high-elo.
Your item builds are solid, the only one I find myself questioning in your past-10 is the Zed build. Not a single active item? Youmuu's/BotRK/Ravenous Hydra are all excellent items on Zed, providing raw damage and an active effect which amplifies his damage-dealt during Death Mark for greater kill potential. Brutalizer is a great early buy, but I certainly would not turn it into a Black Cleaver until much much later- if ever.
The best thing you can do for yourself is die-less. In every single one of your games except for your Twitch game, (only 4 deaths,) you died far too many times, thus implying you made many positioning errors and gave the enemy team an advantage through each of those deaths (gold, exp, map ctrl and objective ctrl.)
I start truly dying after 16 minutes because the opposite team starts targeting my lane. I can't win a single game anymore (could it be because of the end of season4?). I have no fucking clue how I can do so well, get good items and somewhat of a good creep, and never manage to carry my team. I recently played a game as Ryze, and I was ulted by 3 to take me out (WW ult, then fizz, then the toggle of maokai) I was so desperate that i built a Thornmail.
Besides that, I can't even win normals anymore. I used to be winning almost everytime, and on rare occasions i would lose. Now i rarely win in the past 2 days. Could you at least watch a game and help me understand my mistakes?