I have a habit that helps me with this, though I occasionally forget and end up having such a frustrating time that I feel my friends end up tilting because of it.
Basically, between games, get up and do something. Doesn't matter what it is, just take a minute or two to do stuff in a non-rushed manner. I usually either make a hot drink or a sandwich. They take time and are multi-step things I can slowly and deliberately do, while also being so simple that I can do them without thinking about it.
By the time I'm done and have returned to my computer I've calmed myself enough to avoid tilting. This doesn't fully work, particularly if the next game is just as frustrating as the last, but it usually does. If I end up not being able to stop myself from tilting I just stop playing, even if I have a group and they want me to keep playing with them.
But as for your post what exactly are you asking? You said you go on complete tilt, but you also asked how you can get better and carry. These are two very different things. I can carry most games that I play with my friends, but the moment I'm on tilt it doesn't matter how good I was, I'm now bad and I feel bad because of it. Tilt will make you feed, no matter how skilled you are, so if you are trying to get better your first step should be to figure out a system to handle tilt.