How to not care about other people opinions?

So today i was playing League of Legends with a friend. I was playing ashe adc and i had an orianna support. I was doing terrible in cs as the enemy MF was poking the hell out of me and she was up y 20 cs.After 2 deaths from eing ganked y a hecarim. My friend(Playing Elise), was fighting someone and i went in and tried to help her and then she started itching aout how im doing absolutely nothing and that i need to "know my place". I tried fighting ack ut then he said" shut up your ori support is more of an adc than you are(she got 4 kils i dont even know how or why). and when i got their MF(finally) Elise said i stole her kill even though her sorry *** was in ******* gromp. I was in a skype call with that elise and she appeared to say everything in a mocking tone not an angry one which pissed me off even more. i tried to surrender ut my friend was all like "the answer is not to ff its to stop feeding". This ended up making me so pissed off i couldnt play anymore(not like i ever could anyways, jus when i thought i was doing good and had something coming for me it had to get ruined).

Another example is when i was playing jungle amumu and i was having a terrile game were i ended up 0/5/5. This vlad was new to vladimir and i tried ganking him and ended up backing off because the enemy laner backed. He told me that i was "useless". Ive had many more examples in league,

Another example is when i was playing as zed and i was against an orianna mid. Ori was close to her turret and i was behind my wave ecause she was zonning the fuck out of me. My jungler ganked and she backed so he ended up going to the other side and said "stupid zed". From there i believe he never ganked me again.

In another terrible game with amumu, i was failing all my ganks and that and i tried to gank bot and missed my Q and then i started getting flamed like hell by our nautilus support.

I honestly try not to care, i mute them, think about something else, ignore them, everything!! but even if i do ALLL that, the criticism sticks to my head, i end up repeating it to myself in my head and no matter how hard i tried to think about something else, it sticks like fucking crazy glue. One comment is what it takes to make me nervous because if i start diung bad i am always like (they probalbly think i should kill myself of how bad im doing). Ive tried to stop caring but i cant. No matter what i do ,i cant. I just cant do it. And its EXTREMELY hard to say i can because i don't believe deep down that i can. Its an ongoing struggle in my life but it represents itself more in League than anything else.

I always fall off because i can't concentrate because that one comment someone makes ends up taking all of my concentraton!