How to lose 55% of the principal

Some reflections I've been wanting to write about this year, hoping to help fellow newbies like me wake up sooner.
Last night, the market opened high and closed low, so I just went to sleep without looking. Woke up today with a floating profit of $500. Summarizing why I and other newbies can't make money.
First, I'm just a newbie with no skills. I can't read charts, I can't analyze fundamentals, I can't calculate valuations accurately. I love listening to big shots, I love following trends, and I love hot stocks. I adore Tesla's limitless imagination, enjoy the ups and downs of small rockets, fantasize about Alibaba representing the rise of the East, and was once obsessed with Xiaomi's ultimate vision of 'people, cars, and homes.' So in December last year, I deposited 400k, bought Tesla at 432, and also built a position in Xiaomi at 34.1. Tesla kept falling the more I averaged down, while Xiaomi kept rising the more I bought. Then I started buying 2x leveraged Tesla, which also kept falling. That's when I made the first mistake of retail investors.
1. Fighting the trend. Going all-in long during a downtrend, averaging down after small dips, buying more only to see it fall harder.
Meanwhile, my other account's Xiaomi kept making money the more I bought, so I made the second mistake.
2. Crazy margin trading. As I kept leveraging and buying, Xiaomi made an 80k profit, and I used margin to hold 10,000 shares of Xiaomi.
I'll never forget February 27th. Xiaomi opened high but then plummeted, and I got my first margin call. I panicked. Then came the third and fourth mistakes.
3. Chasing rallies and selling dips. I sold during the drop and bought during sharp rebounds.
4. Overtrading. I made over 40 buy/sell trades in a single day, each time selling everything or going all-in with margin.
Like a demon, I sat motionless at my desk, trading with a stern face and pale complexion. By the close, I'd not only wiped out the 80k profit but also lost 10k of principal. I finally remembered the saying:
"The gains you make by ignoring risk will eventually be lost by ignoring risk."
Later, I bought Nvidia at 100, TSMC at 200, Google at 150. Did I profit? No. No ifs. Because I made the fifth mistake.
5. Holding losers too long, selling winners too soon. Right during the tariff war, a golden pit appeared—and I was the one who fell in with all my positions. I held stubbornly without hesitation, only to sell for a tiny profit after breaking even.
That's it for today. Timeline-wise, it's only April now. After depositing 400k over 5 months, only 220k principal remains. Next time: how to turn things around.$NVIDIA(NVDA.US) $Taiwan Semiconductor(TSM.US) $Rocket Lab(RKLB.US) $Unitedhealth(UNH.US) $Alphabet - C(GOOG.US) $XIAOMI-W(01810.HK) $Alibaba(BABA.US) $Tesla(TSLA.US) $Apple(AAPL.US)