I need advice.

I'm in Silver 5 right now, I was actually doing really well a few days ago, I was at 80 + lp, got into promos several times, lost the, but I only had to win one game each time anyway to get back in so it wasn't bugging me that much, but I ended up going on a massive losing streak yesterday, I'm back at 0 lp now, there were a few games where I fucked up, I admit that, it's not like I fed, but I wasn't able to win my lane or have any real impact, I've made some bad plays, like engaging when there was nobody to follow up on it, but that's not what I have a problem with, those losses were deserved by me for playing poorly.

But there have been games where I've totally destroyed my lane, even if they switched lanes, I just destroyed and zoned the new guy, but in spite of how far I put these guys behind (and I literally mean 3 levels, had twice their cs, didn't die and took their tower) my team still manages to play poorly enough to die consistently to a guy who hasn't finished his first big item yet even if I roamed around the map, trying to use my advantage to snowball other lanes, they still die several times to the same guy to the point that I couldn't compensate for it with the lead I had, was I at the wrong place at the wrong time or something?

I know that there's gotta be something I'm doing wrong too during those games, and the blame doesn't rest 100% with my team even though I do feel like a big part of the blame does lie with them, because they die to a guy who shouldn't be able to do much to them and after that even I start dying to them.

In my most recent game I actually didn't die in lane and managed to kill my lane several times, during laning phase I put him behind in cs and he couldn't do anything, on top of that, I froze the lane and zoned him out of the xp range as much as I could, even when he swapped lanes I just did the same to the new guy, but my botlane managed to feed both of those guys anyway, even though I came to their lane several times to roam, those roams didn't amount to much more than scaring the enemy team away, but that's at least something, but as soon as I leave to go farm or help try to help somewhere else, they die, in fact the only ones on the team who didn't feed like the red cross in Africa were Ahri and I, we ended up with pretty much neutral scores and most of or deaths were from after botlane and the jungler screwed up.

But I really don't know what it is, I ping, I type that my lane is missing, I ping to team mates to back off, I tp gank if I'm top, I really try to do as much as I can but somehow it isn't enough, what am I doing wrong? Is there something I've overlooked or didn't consider?

Botlane was already strugging early, should I have roamed there earlier? Like after I got to level 6 or something? I really need advice on how to deal with this, because this exact thing has happened a few times already and I'm fed up with it.

It seriously frustrates me, because I feel like what I've worked for is just taken away from me.

something I notice is that I don't tend to have these problems in normals, if I lose normals it is rarely due to stuff like what I just described, or maybe I just don't pay a lot of attention to it in normals because I don't mind losing normals so I forgive stuff like that in normals, but the past couple of games in normals the only thing I got were competent team mates, I was trying to play jungle and I actually wanted at least one incompetent person in my team so that I could learn how to carry them, but in normals I'm pretty much on a winning streak because the team mates I got the past few games were simply good/decent.

Could it maybe also be that I play differently in normals than I do in ranked? I do know that in normals I'm more likely to make aggressive plays than in ranked.

Seriously though, any advice would be appreciated.