Does anyone go on massive win streaks, then massive loss streaks?

I have like 7000 normal games under my belt so I figured that would be enough time for the system to somewhat accurately track my skill and the game quality to reflect that. Yes, I'm a flex player with 48 level 7 champions so I also get that I'm not always playing my absolute best role and best champion, but this is just ridiculous. It goes from me winning like 80% of my games no matter what role I play and playing new champs I play only dings my winrate a little bit. After absolutely smashing for long enough, I start going down the opposite route where I just lose like 80% of games and get super pissed. Now I get it, win streaks and loss streaks happen and shift your MMR a bit the longer they go on for, but I feel like I'm being moved between playing soccer with my 5 year old cousins to playing against a pro Brazilian team every 10 games or so. My friends and I even joke all the time saying "we better not play League tonight, we shit on a bunch of people last night and you know what happens next."

I love this game don't get me wrong and I think preseason is pretty exciting this year even though it's a huge meme balancing wise, but I'm honestly starting to get sick of knowing the outcome of so many of my games before it happens just based on what type of streak I'm on. It's like I'm playing an MMO and I have to grind to get back to the fun part of playing League, like I'm doing my time for 8-10 games of just getting rekt, only League isn't an MMO and every game is supposedly a fresh start where anything can happen.