How to have fun despite feeding teammates?

I find myself winning my lane most of the time, only to find defeat at the feet of other laners who are ALL twice as fed as i am, despite that i probably roamed and helped them get a kill or two. Despite my efforts, i find myself getting frustrated, feeling like i'm getting the short end of the stick in almost every games.

I'm trying to have fun, LoL is just a game, but it's sickenning the amount of players who don't understand basic League knowledge like ''not feeding''. Why are there so many feeders???? in EVERY games. Is it so hard to NOT feed??? I don't think i ever die more than three times in laning phase, but teammates manage to die over 5 times EVERY time (and i'm being generous, they often get way more than 5 deaths). I don't remember the last game that i played whem all laners were even, a game that felt like a tug-of-war instead of a stomp. But it's always a stomp, on either side.

Do you guys have any advice for me? How to you take a chill pill and manage to still have fun even when your teammates are bringing you down?

Defeats are not what bother me, hitting a wall is what pisses me off the most. Almost every game is like "Woot i've got a seven kills lead, helped my toplane get his tower and a kill, helped bot get two kills and a drag, killed the enemy jungler twice when they tried to invade our jungler and... wait... why does our team still have a 30 kills deficit over theirs????"