I need help with a flaming problem...

Hey all, I need some serious help. Recently in games I have noticed that I tend to flame a lot and this affects my gameplay quite a bit. I have read and watched all of the resources I can find about the issue, and although I have tried out all the techniques I have seen (muting chat; focusing on gameplay, not wins; getting a stress ball; etc.) I am still having issues. The main problem is my friends: I can't mute them bc we depend on communication quite a lot, but they give me a lot of crap for bad plays Let me give you an example of what causes me to rage

I die because of a misplay.

Me in chat: Sorry guys, my bad. My friend: You are so bad! (Half joking, half serious.) My other friend: Midlane [my lane] is so fed.

Sometimes this harassment gets to the point where they post in all chat to report me, as a "joke." I have tried simply telling them to stop, but this does not work. Can anyone think of a strategy to help me get through this, as it really detracts from my play.