One of my friends asked me how I got to plat 3 in around 120 games from silver 5. Saying that his teams are always shit and that's why he's stuck in silver. The thing is I played non-stop for almost 3 weeks during summer, and I can honestly say I deserve this rank, can't say about going higher, as I didn't try to. Now, to my point
Is it a bit unreal to expect your team to do good every single game? Also being toxic towards a team that's performing badly is NOT going to help in any case, I can't stress this enough. Toxicity never helps, it only helps your account to get suspended. I learnt to keep my cool throughout my journey to this elo, and almost every game muting everyone, or individiuals that didn't seem friendly at all, and I focused on the game. If your team is performing badly, help them do better and atleast try to win the game and don't tilt. In bronze/silver it's entirely possible to solo win a game, as I did by splitting if my team was behind, securing objectives, opening three inhibs alone, while my team was dying in teamfights. Some people regarded my behaviour as toxic, but at the end we win the game, and people praised me, and it feels so %%%%ing good to win a game that was seemingly unwinnable.
Also, if you lose 2 games in a row, stop playing the game (or simply soloq) for atleast 3 days, and give yourself a headstart the next time you play the game.
TLDR: Don't blame your team, focus on yourself and don't tilt
GL on the rift!