If you are feeling angry or tilted, I highly recommend doing some exercise.
It doesn't even have to be that much. Just a little. Exercise is incredibly relaxing and can help distract you from that 1/17 jhin, that intent feeding AP riven, or the flaming yasuo. I went on a two hour walk and managed to not lose my shit after my team locked in all melees in champ select, flamed each other for bad champion picks, repeatedly got called ret*rded, and many more annoyances in just one game. For a guy who gets tilted after mid goes 0/3 by 7 minutes, this was a pretty big improvement for me.
Seriously, just try it. Go on a short walk or run, do some pushups in your basement, whatever you need to do.