I'd say a great way to climb out of bronze is to find a Duo buddy. Me and my duo buddy almost never lose because we mostly cover top and mid, top for pushing and getting objectives while mid can keep other lanes in check.
You seem like a decent player, you could do better CSing but that's a detail. I'd say find one or two main champions, and a duo buddy. Learn every lane, learn different playstyles, learn how to build from shop and not have build orders.
If you already have all those mastered, and you have a friend who is equally skilled, you already have the advantage and will win more games.
I have yet to play one game in Bronze where any lane other than my own gets fed on my team. I've fed on some games and did bad on some, but NEVER have a different lane been fed besides mine. All you can do is keep your team united, hopefully keeping them even, and lead them to victory.