Bronze - Gold

Just glancing at your profile on LoLKing, it's apparent that on all of your most popular champions, your kills are roughly equal to your deaths. KDA isn't a perfect metric to measure by, but you will generally see someone's kills equal their deaths when they are right around where they belong. If your K=D in low Bronze, you should be focusing on improving rather than focusing on who did the worst when you lost.

You should also note that you usually average around 7 deaths, which is way too many for a player who claims they should be a full division higher. Having so many deaths against unskilled players could mean that you're taking far too many risks. Or it could mean that you're too quick to give up on the game and go on tilt as soon as someone does poorly. No matter how bad your team is doing, and no matter how many kills you get to balance it out, you should not be dying 7 times in one game in Bronze if you don't belong there (unless you were laning against a Diamond smurf).

You should try recording your games and reviewing them to catch your mistakes. You must resist the temptation to blame these deaths on your teammates. Your deaths are your own fault; they are the result of your own choices. Be much harder on yourself instead of criticizing your teammates. These are teammates that you'll probably never see again. Figuring out the mistakes in their build and in their plays doesn't get you out of Bronze. If you can find your mistakes instead, that'll get you into Silver and beyond. The Tips & Tricks board is a great place to start asking for help with this.

tl;dr is basically you're actually not playing well in your division as consistently as you think you are. The competition only gets harder as you go higher, so if you want to simulate playing in Silver take all of your bad scores and make them even worse, and all of your good scores and cut your kills and assists in half.

People have a good match every so often, selectively remember that match, and then think that they should be higher because sometimes they stomp Bronze 4. You have to keep in mind that the competition you're playing against is easier than where you think you should be so you doing well every so often doesn't actually mean that you should be higher. Like I said, your good scores in Bronze 4 basically equate to average scores in Bronze 1 or something.

The most important thing to realize if you ever plan to get out of Bronze/Silver/Low Gold is that scores aren't how you win. Since you're jungling primarily, your job is to be at the right place at the right time, and to get your team gold while simultaneously preventing the other team from getting gold.

Also, if you can try to force yourself not to blame your teammates and ALWAYS think about how YOU could have played that differently you'll start to improve. It doesn't matter if your promo's had a 3/12 Teemo or 1/6 Tryndamere. Sometimes a feeder game is going to land on your promos. It's just going to happen. It's your job as a person that wants to climb to mitigate their effect on the match and the make up for them as much as you can. Your team isn't what keeps you in Bronze. Work on you, and do your best to accept that sometimes you're going to have bad teammates that you have to try to carry. And you can carry them when you're better than they are.