Then you aren't trying hard enough. In fact, every single mistake can always be traced back to being your fault.
My last match was a clear example of this, albeit Normals instead of Ranked: I was Karma supp, with a Quinn ADC. Our Azir mid fed the enemy Swain, our Gnar went 0/2 against their GP coming into mid game, our J4 couldn't make calls, we didn't group most of the time when it was crucial, and stopped focusing their ADC who snowballed immensely. Every opportunity to focus the priority targets I either failed to open opportunities for my team or peeled the wrong target. If it wasn't obvious, yes, we did inevitably lose (though we did secure the first 3 dragons, we lacked in pushing as a group among the other important aspects of playing).
I'm glad you're not the way you portrayed yourself when making this post, since you show signs of humility.
If you're willing to work cohesively with your team, play smart, and encourage your team mates instead of hounding them when they mess up, along with several other important factors, you'll be halfway out of Bronze, guaranteed.