Help, forever Silver in elo freefall

Hey all, my name is Jello and I have played LoL since S4 around the launch of Gnar. In the last year and a half I have mained Lux support and have found that I am quite better than most of the other players I encounter on the rift. At the moment I feel that I win lane 75% of games, get my mid and jungle snowballed and then our team falls apart mid/late game. Most often I find my teammates far out of position, fighting with the waves are not in a good position, only moving forward in fights, never disengaging and chasing kills. Checking my match history compared to others in my elo, I found that in 20 games I bought 72 vision wards compared to the average 3 I saw on other players last 20. I run windspeakers blessing and have run Ardant Censor as core before it became strong. I know I cant make players on my team work together, trying usually just results in tilting them. What can I do to make sure that my team is less of a factor in my wins and losses. Generally speaking once all of the t1 towers are broken, and almost always once the t2 towers break, my team runs around like chickens with their heads cut off. I secure the majority of dragons and barons when I play. Playing another champion is not an answer I'm looking for. Please help get me out!