Need Help on Improving!

Hi so a bit about me I've been on and off league for about 2 years now and I did play a bit seriously s6 and reached silver. I took a 9 month break and noticed that players have improved a lot. Currently I placed into B5 and climbed my way into B1. I noticed while in B1 I'm amazed how some people are in bronze, and sometimes how they even got to B1. As I am coming closer to winning and losing lp now usually 21-23 a win and depends 17 or 18 a loss. I completely understand i'm bad at the game and want to improve. I also don't exactly want to main adc as It seems I cant carry my way out of bronze. Should I take the time to practice a bit more mid/jungle? I do feel the most comfortable playing adc but im just not sure I can carry my way out of bronze into silver. My op.gg is ninocappucino na. Or should I stick with it with adc and just keep on improving. Thanks.