Database mysql process overloading after migaration

I have a website A. Then I make a clone website of A (website B). They are wordpress website. I hosted them both in shared hosting. But now website B always make overloading the sharedhosting server due to database mysql process. Here are some screenshots: https://prnt.sc/26lotyb https://prnt.sc/26loucm

This is what I did to clone my site:

1. Export database from phpmyadmin
2. Compress and download files in public_html
3. Upload, extract files in public_html, import database, connect them.
4. Run SQL command to replace domain name
5. Use plugin Better Search Replace to replace needed things. Then website B run well, but after 2 weeks, it made this error.

Thank in advanced everyone!