If you are hardstuck negative winrate, and it's actually all your teams fault, remember this:
Statistically, you have a lower chance to be matched with idiots than your opponents, since you're better than everyone else.
Your team is: "You, the amazing player worthy of being 2 whole divisions higher and 4 idiots." Their team is: "5 idiots"
So you being stuck shouldn't be mathematically possible, since your team always has an advantage with you on it.
Unless...
And here's the kicker
You're one of the idiots yourself....
Focus on your own mistakes. Focus on your own play. Don't blame everything on your team or the matchmaking. Start improving! Then you will actually climb.
qR combo and get them all down to half health, but my adc is afraid of getting bursted and only goes in when I pop my passive.