Mute self option

I get extremely salty in ranked games when my team is extremely bad, but I understand that telling them over and over just how bad they are isnt going to help them get any better. I'd like to have some feature that I can click in a moment of realization that just mutes me for the rest of the game. My natural anxiety gets the best of me and I'd prefer not to get banned. I just get pissed. I ask people to mute me most games before the match, but they usually dont.