How to CARRY games - SOLO B3

I'm having a lot of trouble carrying games, and even though I could be like the stereotypical Bronze player who is frustrated with his team all the time, I know the problem here is me. No matter how well I play I can't carry hard enough. I try not to die and push objectives 24/7 but it always feels like i'm the only one trying to do this whilst the enemy team is always stopping me at my every effort. I try to have the mindset of "They are Bronze too" but it still feels kind of impossible. Usually I have one chance to bring the game back but I can never end up closing it (for example if I was killing nexus with almost no dmg while my team trys to get kills as I desperately hit the nexus) I usually play Tanky champions but idk if that's viable anymore, whats a good score if I can't win any games?