Why Do I Always get Placed with Feeders in Ranked?

70% of the time I ever play ranked there will always be at least 1 lane that feeds and loses us the game if not the other two at the same time. I usually either smash lane or I lose it by 2 or 3 kills and try to wait for a jungler gank, playing safe and farming. Generally when I lose lane like this I'll be lucky enough to have a teammate who is actually somewhat strong, but when I'm the one who wins lane, I go to roam just to find out that the Katarina on the opposing team is going 8/1 and their jungle is going 5/2 and their bot is also doing well. Then I'm stuck trying to babysit my teammates so that they don't feed to much and trying to defend towers and stuff while since they're so ahead, they can just fucking dive us no matter where we are and win and then my teammates will misposition or go in 3v1 or something stupid continuing to feed. People will even go as far as to say "We all fed" when I'm going 3/4/1 and my kills were solo kills while all my deaths would be because there's no mia, the enemy will dive me without second though while being 3 levels ahead of me. It's funny that this happens way more often in ranked then it does in normals. I'm stuck in Bronze 3 because I'll win a game from either carrying or getting lucky then the next 3 games will just be me stomping lane then getting crushed by the stupidity of my teammates letting the enemies do whatever they want.

    I would really REALLY appreciate it if someone told me what I was doing wrong or how I could really improve my gameplay so that if I'm in these situations again, I'll actually know what to do, and yes, I've tried roaming and all that and it will kind of work but most of the time they escape or they kill my teammate and I'm like fuck this shit I'm out. (Side Note: I would be open to coaching for sure if anyone would want to help me with my errors.)