The loss streaks I experience are statistically unexplainable.

Hmm. I looked through your archive and didn't see any 18 game losing streaks...

You have lost a lot of points recently on your blitz rating. It is down almost 200 points in the last month to its current 644 level. However, that kind of fluctuation isn't uncommon.

It is usually followed by a good winning streak.

I've played every day for the last 5 days. If you want me to be specific, I've won only 17 out of my last 50 games. This is after a 200 point climb. BUT THIS IS MY POINT. If I'm at my rating cap, why is the variance +- 200? It's ridiculous.

There is no rating cap on players. People drop 200 points all the time.

Why it happens isn't clear.

And I'm saying it's fishy. I'm not full on accusing anyone of fair play violations, but I don't believe that the algorithm does what it's portrayed to do.

I think it might been because since it's almost summer break alot of kids in the us have started playing again I also had a 200 elo loss apparently alot of people have had 200 elo drops

It's its either something like that or I just dropped Elo cause tilt :/ tbf I also almost hit a beak (one game away )

There isn't a "cap" it's just that when you improve it takes a while to get better enough to stay at your peak it's normal even for 2000s you don't always see immediate benefits to studying to even if you are getting better (plus when you try new things you tend to loose more )

Tlusually after a peak there's also a moderately big tilt after I tilt almost every time

Tbh your also playing blitz as a 600 it doesn't work for everyone I think playing blitz at 600 can be helpful but you have to be careful to not get into any bad habits or you could accidently perma tilt yourself switching and experimenting with time controls might beba good idea blitz workd for some rapid works for others .

The OP seems to forget that chess is being played by people.

Let's assume that your rating has reached a point where you are losing roughly as many games as you are winning, more or less.

When you lose a game you get annoyed. That makes you more likely to lose the next. When you lose two in a row, you start getting frustrated, again increasing the chance of a blunder in the NEXT game. Three in a row might make you impatient and angry. And so on.

Wins tend to have the opposite effect, making you more optimistic and more focused.

Thus winning or losing streaks tend to assume a certain "inertia" or momentum of their own.

Exactly.
When on a losing streak it can seem one can't win a game to save one's life
and when on a winning streak it seems one can do no wrong.
I've had the same experience with the tactics problems.
Moral: when on a losing streak - pause the session.
Up out of the seat - time for other things.
It may take exercise and meals and a night's sleep and more exercise and a lot of other things.
To get the mindset into where you want it.
If you're playing the same opponent it can make the streaks worse - for somebody.
Try a different time control. Including faster.

I speculated that on average, the rating fluctuation is +-237...

People -- I've been through this before.

If you want different reasonings your not gonna get one the sad truth is if you suck at chess it's your own fault and they gave you actual statistics if your perma tilted that's your own fault

I just won 8 games in a row. Players playing at on average 60 percent best moves. Last 18 games before that my opponents play at a 75.5 percent best moves (including wins and losses). Does that statistic make sense? Because you'd think that they would be around the same range -- given it's not that different ELO...

• Sample size "I just won 8 games in a row." 8 games is too small a sample to draw conclusions. Statistics only "work" for large sample sizes. A sample size of 30 is the smallest you could consider before even starting to draw any conclusions. Very superstitious people think just two events makes a trend. So, you hear the fallacious reasoning from them "the dice just came up snake eyes, the next roll cannot possibly be snake eyes."
• Independent events Statistical analysis applies only to independent events. Assuming you are playing random people and not the same person repeatedly, your opponents are independent. However, you (not the opponent) are the same in every game and thus are not independent. If you are playing poorly one loss follows another, if you are playing well you go on a winning streak.
• Draw effect It's much harder to win a game than to draw one, but the Elo calculation assumes that two draws is the same as a win and a loss. It's not. So, if you happen to play a lot of stronger players, your Elo will go up, whereas if you happen to play a lot of weaker players, your Elo will go down. It doesn't mean anything about your chess strength.