stuck on 500 elo

Even at my level below 400 blitz (and above 400 rapid) opponents usually don't make obvious mistakes if I play just normally at the opening. Often I like to play weird, or I play defensively trying to bury my king between other pieces so that my opponent has to think of a way to fight through and I maybe get a chance at a counter atteck.

I think you're playing with the wrong mindset. If I lose it's ok, often a loss can give me inspiration or good feeling if the opponent was just too strong. You should just enjoy playing chess and treat every game as a new adventure.

I go into every match with zero pressure expectation. That's when I can play more freely and feel more comfortable mentally. Also I have zero elo anxiety. I sometimes can lose 7-10 times in a row but I always can bounce back after it because I don't care about the results.

Whenever I start working with a new student who is stuck at a plateau, 9 times out of 10 they are playing 20 blitz games a day and doing zero deep analysis of their losses. Swap to playing just 2 rapid games a day, but spend 15 minutes analyzing each game on your own before checking the engine. Your rating will thank you.

I have the same feeling. People with old accounts playing at 80% accuracy yet they're stuck at 600, it makes no sense. They blunder a piece however then they proceed to play like future GMs. My guess is that they turn on stockfish at certain moments

90% of games below 1000 elo are decided simply by 1 move blunders and to be totally honest here this happens at my level too! This may sound extremely obvious but simply by just reducing these obvious 1 move blunders you'll easily break this plateau. This can be done simply by making sure none of your pieces are hanging before every move and checking for opponent threats not just your own ideas.

Another mistake I see a lot of people do is they just spam 20+ games everyday and expect to become better like that. Obviously playing more games helps but when done too often it can lead to tilt and mental fatigue which is definitely something you want to avoid. I noticed you play way too many blitz games(like @ChessMasteryOfficial said) in one go instead of playing rapid. Playing blitz is fine and it definitely helps with your intuition but you should probably be playing more rapid games than blitz games if you want to improve. After all if you have time to play 20+ blitz games then you've definitely got time to play 1-3 rapid games.

Last but not least you're entering a stage where tactics begin to play a larger role. You need to develop stronger pattern recognition to improve these tactics. I personally like to use chesstempo and Lichess as their puzzles are great and the custom puzzles on chess.com though you only get 3 of them free a day. I have a blog called 'Every Single Chess Tactic Explained (Yes, Every Single One)' where I cover all 30 chess tactics with explanations, examples, and puzzles to introduce every single one to your pattern recognition which like I said is very important. Obviously this isn't a full-on tactics course but rather an introduction and kick-start to your pattern recognition so it's still important to do at least ~10 puzzles a day on a good chess puzzles website(again my personal favorite is chesstempo.com). Now I know you mentioned being a casual player but even casual players can easily break the 1000 elo barrier with the correct training.