Please tell me how to solve dandruff and dead skin cells.

Previously, I used to wash my hair every day in the summer and every other day in the winter. However, recently, less than a day after washing my hair, I started experiencing itching on my scalp along with dandruff of various sizes.

Recently, I noticed a lot of white dead skin cells coming off on my body as well. I enjoy going to the public bathhouse and shower every day, but one day, while putting on and taking off dark clothes, I found white powder stuck all over the inside. I was shocked. And it was even the day after I had just come from the bathhouse.

I’ve noticed that I have a lot of dead skin cells and dandruff all over my body now, to the point where I can see it. I searched on YouTube, and it says it could be due to stress or a weakened immune system.

It's been over two months now and this is still ongoing. ㅠ If anyone has experienced this, please leave a comment letting me know how you solved it or if you know a good solution.