Im Sick Of These Teams. It feels like it keeps getting worse.

Look, i know part of it is to blame for me not being good enough at the game but it just ruins the game when you have teams who just don't... fucking work out. it feels like you are just wasting 30 minutes dying over and over to a fed adc or jg while your team picks their noses while you make up a ton of the kills and just general are the only one doing work. i can understand being new and stuff but fuck is it annoying. if you look at my last 2 normal games the latest one had 3 people leaving from like 10 minutes in after my pantheon left after calling me a r%%%%% for ganking his lane (stealing his kill?)... then the pantheon came back after the other 2 were long gone and kept saying "r%%%%%s noob game gg im carrying (n word)" and then continues to run it down botlane. me and the jhin just gave up. and the last game where my team bothered me was just me making up like 99% of the kills and being so ahead of everyone objective wise and kill. i literally made up 100% of the kills up to around the 20 minute mark where i began to fall off due to them being too strong. like i said before i do understand its part of my fault for not being good enough but does anyone have any tips for dealing with this issue and not tilting?