Wouldn't your MMR be incredibly bad if you dropped from diamond to silver? Paired with the role swap it would be a nice idea to start from a fresh account.

You should also experiment with other ADCs, especially ones without the fixed aa rate that jhin has, which will allow you to focus more on the wave management rather than ammo/ability management.

With macro try to ping your supports ward item and remind them to use it more often if they aren't, and buy more pink wards yourself, so that the greator vision you get eliminates the need for as much jungle tracking.

ADCs got a buff during the durability update, so they don't get one shot as often and can deal more damage during teamfights, so I'd say it's a decent time to be trying it out.

If you manage to take bot lane tower during laning phase, ideally both you and your support would rotate mid, where you would focus on farming safely and going for mid turret, as well as being able to easily join any fights that break out around objectives.

During the game check out who on the enemy team is a threat (e.g. mid assassin/jungler) and make sure you know where these people are during teamfights so you can position away from them, since a dead adc cannot do any damage.