Getting mad is completely normal but it will probably affect your gameplay.
Whenever you open up brawl, try going into practice mode and re-doing your strings/combo's or whatever on bots and see how it goes, if you can do that flawlessly, go into an experimental match or 2.

If you won both experimental matches, good for you, try and play some ranked now.
If you didn't win both or won none, try and look what you did wrong in a replay or ask feedback at the end of a game and hope they won't trashtalk you.

If you notice that you are playing really laid back in ranked games, try and sit up straight (or whatever you feel most comfortable with) and try to play like that.
If you are not laid back and are trying to win, try and figure out what kind of playstyle your opponent has so you can (try and) counter it.

I'll make a little list on how to deal with certain playstyles:

Agressives people: Parry them, wait for them to miss an attack and then punish them for it.

Defensive/Passive people: Act like you're running towards them/Chaindodge twice and then spot dodge or try and pressure them so they dodge/jump away and then punish them for doing so. Berthen made a decent video on how to counter passive players.

if I forgot any kind of playstyle which is low-key serious, please let me know in the comments so I can add it;

So after some looking through the comments, I saw people wanted a part on how to get less tilted in 2v2's!

With tilt in 2v2's I think of people getting hit (and possibly killed) a lot by their teammate, what I would advise is: Coordination, try to talk with your teammate and make up strategies. For example: Let your teammate stay on the left side of the map and you stay on the right side, both taking on one enemy at a time and if the other one gets into trouble, make sure you let your teammate try to save you.

If that still doesn't help, try finding another partner and play with them!

Try and play ranked for Glory and maybe a new highest peak, but don't try to do so to impress others, try and do it for yourself.
Whenever you play ranked you should be 100% prepared to lose 30 elo everytime you start a match, talking about elo, elo isn't anything that really matters. It's something that's supposed to rate your skill level;

but let's say that you are really good at reading but can't seem to be able to deal with spammers, then it's not really that easy for you to get out of gold/silver or something.
Try and learn how to deal with your current rank's most players and as I said before, try and look what their playstyle is.

Shouldn't be too big of a deal since if you're at least a bit decent at the game and have some time to spare, you can get the lost elo back by playing more games and (with the tips I've given before) win them more consistantly.
Also, my good friend Red told me that it would be best to stop playing ranked for an hour or more if you lose more than 3 games in a row, since you'll just start raging more and more if you keep on playing and losing elo.

EDITED: If you notice the enemy trashtalking you after the game, just leave. There's not really a lot of reason to react to that since you'll just bring stress upon yourself.
A good tactic to completely avoid the enemy after games is to spam c/confirmation button until you just get back to the ranked screen.

Getting trashtalked isn't that bad if you think about it.

Not sure if this really helped a lot of people, but I did my best.
Thanks for reading and have a nice day!

-Nessmonk