Focus on yourself. I know it's hard, but allies are always going to change and rotate around. In looking at your profile (small sample size, I know) you have a lot of room to improve. Your winrate is roughly 33%, which needs to be at least 51% to start progressing through the ranks. Figure out what roles you're best at and work on them.
You have to play a style that I call intelligently selfish. The goal is to basically singlehandedly carry a game on your shoulders, but you do it by making your allies stronger/more fed than you. If you're mid, dominate your lane then start roaming to top/bot and start feeding them kills. Do everything you can to make your allies stronger and you have a much better chance at winning!