Having a problem with matchmaking balance...

So. I've been getting matched with quite a few players that are consistently showing me that they obviously don't know what they're doing. I got up to my Gold 4 promotion series, and failed it right? After that point on, something happened, not with me, but with what mmr players I've been getting. My recent matches I've been doing good in lane, few mistakes, good roaming pressure when I'm not playing adc, warding. Everything's been fine. I keep seeing people go 0/9 and 0/6 and 0/5 only minutes into the game. I've started to watch their normal gameplay behaviors, and haven't said a word in chat. I like to focus on the game, not the little box of toxicity. I keep seeing them dive towers when they really shouldn't, multiple times a game, 2v5'ing. Just extremely low elo mistakes that I don't think should be made here. So I checked my OP.GG. My MMR has apparently tanked from 100 points above average to 100 points below average. I can see the correlation between the MMR and the players I'm getting. My silver 4 friend has a higher mmr currently according to OP.GG. So I essentially have to win more games to raise my mmr, but that's practically impossible with the amount of players that have been, albeit, unintentionally feeding. My main question is: What's with gold 5? Is gold 5 the elo people reach from silver, and just stop caring because 'I got gold, I'm good and deserve plat.' So then they do stuff like katarina top into Irelia? Anyways, anyone have a fix to how I can get better people other than winning? Would getting more objectives killed under my name help me out a bit? Or Assists? I honestly don't know what I can do more to help myself.

Summary for those who don't want to read a blob of text: What is a way to further my MMR when winning games with the current MMR is nearly impossible?