Yeah..
Here's the thing man, and I know its already been said but Im going to add my .02 in here just the same. If you're losing, then you're losing. You weren't the superior player and the other guy the scrub if you couldn't handle him mashing. If he was beating your + frames then you need to tighten up, because realistically, most good players absolutely salivate at the chance of meeting players who want to hit buttons when you are plus. Sure the mashing may catch them once or twice, but they adapt. Once they adapt and realize you're gonna be on buttons they will just tear you to pieces.
Sounds like you arent as good as you think you are man. I dont mean that to be hateful or blindly insulting.. but if you're losing enough to mashing.. then that's a problem and a weakness you need to work on. +frames arent a magical guarantee. You need to work on your frame traps and tighten that pressure up. Any good player with any sense is going to occasionally check your pressure and really good players will pick up on your game being loose.
I dunno man. Ive made my share of excuses, but it just ultimately boils down to winning and losing and that's about it. If you lose to a certain player regularly, you arent better than them and they are just 'playing the game wrong'.. You are a weaker player than they are, or some part of your game is weak to what they're doing and at the end of the say, regardless of how you got there, its a Win or a Loss screen and outside of the opponent LITERALLY cheating in some way, you earned the screen you're seeing.
Everyone has bad games occasionally and loses to a player they will normally beat 10-0 or the like, but if this happens enough to cause this kind of reaction that doesn't sound like what happened.
Some of the posts I read are a little harsh, but that's just how it is. I made excuses and got called out for it.. As a result I sat down and re-evaluated what I was doing and how I thought about things and I bounced back as twice the player, and have continued to improve since. In the heat of the moment I scream and yell as much as anyone, I throw shit and I go through controllers like tic-tacs, but I know its still just me. I look at what beat me and I work on how to stop it beating me the next time, and if I lose to something, it's cause the other guy was just better vs me.