How do you put yourself in a position to carry games?

I have gotten to Gold 5 and then stopped playing for two seasons in a row. I know, I know, "You should have just kept playing if you wanted to be better." That's all fine and dandy, but I have other things I wanna do, and tbh, I don't mind being "ok" at this game. Ever since I started playing this season, I have done nothing but lose. Placement matches were expected to go south, those never go well. But it doesn't matter what I play, or what I do, I cannot stop my teammates from doing something stupid.

" You can't control your teammates, focus on your own gameplay." - Only, non in-depth cut-and-past answer I've been getting

I know you can't control people, I get that, but how on Teemo's demonic soul are you supposed to carry a Rageblade Ashe? How do you convince your jungler that maybe invading their jungle when you are half health is a bad idea? In past seasons, I have never really had this problem before, and if I did, we solved our problems as a team.

Now... I don't know what the hell is happening.

I can play every role except jungle, well enough to secure a victory. However, I don't know how to shove a victory down my team's throat when they are doing nothing but feeding, or not cooperating. Thirty minutes in, they are at Baron, and the jungler goes bot to farm. Really? What am I supposed to do about that? I will admit, that there were some matches that I was obviously playing under tilt (playing champs I don't normally play, playing late game scaling champs, etc.), but right now I am at a loss for what to do.

I know that there is a method to just solo carry, but given the extra snowbally nature of this season, and my lack of skill, I have not found it. I can't go practice in normals because my mmr is so low from not playing the thing (Teambuilder OP), that I either face, or have nothing but bronze level people on my team. Some aren't even level 30 yet.

I'm not saying that my teammates are 100% why I'm in this position, I've still got things to work on, and I know exactly what they are. All I am asking for is advice to carry out of this mmr pit that I am in. I'm honestly inclined to just wait for Solo q and try again, because I'm pretty sure that I have been running into dynamic quers....