How Do I Prevent Tilting?

So, I'm a fairly new player to the game, League of Legends. I have been playing for almost three months now, and I have just started to play ranked. I noticed in videos that I see on YouTube, and the such, that these players don't tilt often, and they're able to stay focused on the game, and I also know that I tilt very easily when it comes to getting flamed, and I know I tilt hard at that, although generally I can ignore flames from the enemy team. It's usually when my own team starts to flame me that I start to tilt. As you have probably assumed by now, that my new experience with ranked has proven to have burned my house down with all the flames that I have gotten from my own team, whether from mistakes I made, or mistakes I didn't make. Now, before someone says anything about muting everyone in the lobby, I want to make it clear that sometimes I can't do that to my own team, as I have duo'd, and plan to duo, with other people in ranked, and sometimes, these people get pissed and flame me. In addition to that, I also have people I hang around with in the real world that play League as well, and sometimes they will walk past me, watch me for a second, and make a remark like "Wow you suck," or "You could've done blah blah blah to have come out ahead." And I know these comments shouldn't get to me, but they do, and I start to tilt thinking about what I could have done in that situation. And then while I'm distracted with that, I go and make another mistake, and I get flamed by my own team, or I curse at myself for making that mistake, and then I tilt harder thinking about that mistake. The rest is pretty much self-explanatory. Now finally, my question to you all is: Is there any tip or thing I could do besides muting that could prevent me from tilting, or maybe a way to prevent me from tilting as hard, and allow me to focus on the game? This is by far my biggest problem when I'm trying to improve my ability in the game, and I have yet to be able to find an effective way to work around it. I know this question seems pretty redundant and self-explanatory, but I haven't been able to really discern a solution or way around it, and I was hoping somebody here on the Boards could offer a solution?