I just looked you up on op.gg and on lolking and I've noticed several things you can improve based on that. In your most recent 20 ranked games you have played 13 different champions.
Your item builds are kind of poor in many recent games, they are mostly right but there is at least 1 missplaced item in most of them. For instance on your zed you have no brutalizer but you do have black cleaver, most people on zed either go for brutalizer first or you get cutlas, then you build the other. You really need the early CDR and the early pen on zed to lane well.
Your Riven has the same problem, you really need to prioritize brutalizer on her for the CDR and early pen, its important to snowball early game. Your core is Brutalizer + Hydra + Maybe CDR or MR Boots depending on how fed you are getting.
Your deaths in games you lose are extremely, extremely high. This could be for a few reasons, either you try to save team-mates from certain death too often and thus end up dying yourself. Or reason 2, you push too far on the map without vision. The first thing you can solve by following this rule, never fight a fight where you are outnumbered, a half health champ counts as half a champ, and if you are fed then you can count as 1.5 champs. There now you will die less from that. To die less from lack of vision start upgrading your yellow trinket at 9 and try to get in the habit of using it on cd and try to develop the habit of looking at your map.
If you are split pushing you need to make sure that your team is shoved up at least as far as you are, this way if you end up dying your team will be shoved far enough for it to be worth it. Never just shove a lane while all your team is backing thats awful.
Unless you just really, really enjoy hard champs I would play less of them, I wouldnt play Draven, Zed, Leblanc, etc. Or any champ that gets owned in lane like Poppy until you have a really good grasp of the basics.
My last piece of bronze advice is to play more aggressive and trade more, many many people in bronze let themselves get hit when they are farming, you can shove people out of lane by missing 1 or 2 cs and really chunking them hard, this will give you level leads which are sometimes more valuable than the gold you would get from a kill. For instance at level 6 Diana gains like 300 damage, this would be the equivalent of ~400 ap worth of stats on her q and w damage. If you hit 6 first you can leverage it into huge leads on many champs.
And advice for all ELOs, work on last hitting its worth SO MUCH, 10cs is worth a kills worth of gold, if you are up 30cs and even on kills you could be almost 1k gold ahead of them by yourself.
And lastly not sure about what masteries you use but 21/9/0 is basically the best for every champ mid top and jungle with 0/21/9 and 0/9/21 being good on supports.
Also you have 5 losses in a row recently, I didnt notice any other super streaky areas in your match history but if you are getting tilted go for a short jog around the block or something and clear your head.