I can totally relate to you, OP.
I got the 3ds version when it came out, and I played For Glory every day. It was fun because, aside from the first few months of Brawl, I never really had the ability to play other people before. However, I found out that I'm stupidly competitive with this game, and when I saw that I had done over 1,500 games with a 94% win rate, I developed a huge ego and got frustrated whenever I lost because of how many games I had to win to regain that ratio every time I lost a single one.
I consider myself to be a very calm person. I don't ever recall getting angry at or around other people, and whenever I lose at a sport or a competitive game I sit there and think about what I did wrong and what I can do to do better next time. However with For Glory, something in me clicked and I stopped doing that. When I started to lose, I would get angry. When I started to get angry, I would blame the other person (even though I knew it was entirely my fault for losing). Every time I caught myself getting angry or becoming salty, I'd instantly call it childish and dismiss it, bu it kept on happening and happening.
Third month into the game, I threw my 3ds, just like you, only it broke entirely. The experience shocked me, because I never hit or destroyed something in rage before, but I decided I wouldn't buy a 3ds to replace it and continue my habit.
7 months later, I bought a wii u and smash bros, and here I am, 2 weeks later. I've been playing For Glory non-stop and I'm already seeing myself repeat the pattern. After about 500 games, I had around a 84% win rate. But then I had a bad losing streak, mostly due to bad connection, cheap tactics, and bad decisions on my part fueled from frustration and impatience, and I went all the way down to 73%. I told myself I wouldn't care about the win rate, but I apparently can't help it. And because of it, I find myself getting angry at stupid loses again over pointless statistics.
3 days ago, I fought a really good opponent who I felt was clearly better at the game than me. I like to take these opportunities to try and learn and get better, despite the damage to my win ratio. This was no different, but something about the way this guy played pissed me off. I got livid over nothing. And I ended up punching a hole in my wall.
I want to say I'm going to quit For Glory because it's making me act in ways I've never done before, but the entire reason I got smash 4 was to play against other people online. After playing Anther's Ladder for a few days, I much prefer to play friendlies over For Glory, but I don't always want to spend the time and effort to add someone for a friendlies. Sometimes I just want to come home from work, turn on the system, and just play a few matches without much effort or interaction.
It's times like these that I really wish there was a smash scene where I lived, but there isn't. I don't have the ability to travel around and do tournaments in person. So If I want to play Smash, it will have to be online, and most likely in the format of For Glory.