I should honestly just purposely throw every goddamned game since Nintendo refuses to give me a single fair match. I'm just going to squidparty and ruin every single fucking game until my glicko resets and they'll stop fucking me at every opportunity.
My dude, I can understand it getting extremely frustrating when you're playing really well, but the team let's you down time and time again. I myself sometimes have this too. However, there is probably someone else on your team who also is not having a good time, because they have been matched above their skill. Matchmaking is quite lacking in that regard, but don't let it get to you. If you just keep trying the same thing over and over it's not gonna magically work after the tenth time right?
May I suggest you change your approach when such things happen? From what I can see you're mostly playing a slayer role right? Maybe try being more supportive for your teammates, don't rush to the frontlines alone, but stay back a bit with your team to defend or push together. Or slightly more extreme, stick to one of them and try to help them. Trying to guide teammates by signaling 'This way' also helps (I sometimes like to spam it a little when my teammates aren't coming after a while)
Or you can simply try and switch your playstyle: slayer not working out? Well, how about going more defensive or supportive? Not only to change your experience, but this might also affect matchmaking. The mode might also make a difference sometimes, there's plenty of choice in this game: turf war anarchy open, anarchy series, salmon run.
Lastly, are you only having fun when you're winning? Or is a cool play or close game also something that makes you happy? Because winning shouldn't be your primary fun factor imo. Try doing some degenerate shit, think outside the box. Some of em I do myself are: Torpedo spamming, running around the long way in Tower Control (not always works, but more fun than simply charging an incoming push head on), enemy base invasion, Zipcaster shenanigans, ink mine tower stalling and I'm sure there're plenty more tricks.
Anyway, if you're up to play sometimes, feel free to dm. (Offer stands for anyone here tbh) I think I can handle myself decently well in a match. And remember that games should be fun first and foremost (imo at least)
PS if this is turf war we're talking about, I have no clue about how to consistently win that. That mode is a mystery to me, so I can understand if back-to-back losing there can be kinda nasty[/SIZE=1]