Good response, i like that. Yes, even high elo players struggle with your problem and yes not every game is winnable. Just have to recognize which games are and which games are not.
What roles do you main? Here is a specific tip on how to climb. Main one role and one champion only (have secondary role and champion as backup) and spam them. Bruce Lee once said, fear not the man who practice 1000 punches once, but one punch 1000 times.
As a jungle/support i can tell you to lead with examples. Supports like leona, morg, blitz, alistar can gank and win lanes so hard it eventually snowballs the game. But lets say you play morg (your teammates comp doesnt matter). Try your best to win bot and put pressure on your opponent (you are at 90% hp while enemy is at 30%). Force them back, by mobility boots fast, go gank mid. Ward up and always go to your teammates to setup something. Top laner afk farming? Go hide in a bush, wait for enemy team to come and do big turnarounds. Adc is behind and needs to farm? Go 4 man push and let him farm while you make plays with bind and ult.
Always play vs your opponents and if you are good enough, the enemy team will crumble. Every time a enemy adc shows up, he should be afraid of dying, put pressure. If you cant do that, then you are not ready to climb. My blitzcrank can.
Also, buy pink wards, vision win games. At least 3 a game.
PS. Challenger players have to 1v9 diamond/master players. Surely you can 1v9 silvers if you deserve gold? ;-)