Some are more volatile than others and sometimes you can't help your emotions so don't feel bad when they come out. They are just electrical signals in your brain going off -- they will subside eventually so try keeping your composure until they do or take a 5-10 minutes break to get some air or water.
The above is just a bandaid and won't really work for severe tilt so if you're one of those people you need to look inside and figure how your emotions are sourced and channeled. I've played with some bad tilters and a common thing I hear is when they can't perform to their expectations/goals (which tends to be really high)> they start to feel bad > they play worse because they feel bad. This is a negative feedback loop and you can't get out without changing either 1) expectations and/or 2) the channel.
As an example - If you're new and expect to play superstar games with superstar teammates then you will be disappointed because you guys are just trying to figure things out and everyone has their own idea on the best way to win. An alternative and much better goal is making progress, no matter how small, with your own performance as well as getting closer to aligning the team's playstyle. In short -- set lower standards, jump over them and say ta-da!
If you find that subconsciously you can't really lower your expectations and get tilted no matter then consider consciously channeling that energy towards something productive instead of self destruction. So instead of feeling bad about yourself you can take your anger and use it a fuel to watch more demos, grind your mechanics and find common ground with your teammates (get good). These are examples and you're going to have to make it work for your own circumstances.
Lastly, don't give up. You can get better and the worse thing you can do is to give in to the tilt and, even worse, spread it to your teammates.