Chew on this, Ragers, Flamers, Blamers of all colors.

Every body loses. Average is around 50% winrate. Losing a game is normal, get over it. There is no need to over think it, thinking "It's Toplane's fault, they fed Darius" because for every time your team mates may have costed your team a heavy blow, theres an enemy who does the same in you're winning games. There is always going to be a better player, a better team. It make's no sense if you get angry about it, its just making the inevitable even more incredibly unpleasant for every party involved.

Don't be angry. Just take the loss, play another. If you want to win more, try to think about what you could have done better, not what your team did, because chances are you won't play with them again and its garbage info to know. If you won lane, how could you have abused your lead more? Was there ever a point where you didn't know what to do? Think about what you could do. Did you zone the enemy or did you just let them free farm even with your lead.

TL:DR Don't rage, it's pointless. Like life, no meaning. (Hooray existentialism!)