Thanks for answering.
Considering you're struggling through Silver, I'm going to give you the advice everyone does, which is to focus on 1–2 champions most of the time. It doesn't magically fix your problems, but it gives you a base line. Really take the time to understand their kit, situational rune setups and item builds.
Vision is good, but as an ADC you have two (three) very important skills you need to learn and/or constantly improve: farming and teamfighting (bonus for kiting, which is just the basic skill you'll work with 24/7). Every single game has an early game and an ADC without farm is useless. An ADC with farm who can't teamfight is useless too. Learn to dominate your lane and learn to not feed once you're losing lane.
Your mental issues are pretty common, as around 75% of performance these days is based on being confident in your own ability to perform under pressure. Easy solutions are to either become a very proficient one trick so you can be confident in your ability to perform your tasks well no matter the circumstances (farming, kiting, teamfighting) or create a positive player identity (the Farmer, the Teamfighter, the Duellist, the Shotcaller etc.) and work on that.